您好,登錄后才能下訂單哦!
Apache Commons包含了很多開源的工具,用于解決平時編程經(jīng)常會遇到的問題,減少重復(fù)勞動。下面是我這幾年做開發(fā)過程中自己用過的工具類做簡單介紹。
組件 | 功能介紹 |
BeanUtils | 提供了對于JavaBean進行各種操作,克隆對象,屬性等等. |
Betwixt | XML與Java對象之間相互轉(zhuǎn)換. |
Codec | 處理常用的編碼方法的工具類包 例如DES、SHA1、MD5、Base64等. |
Collections | java集合框架操作. |
Compress | java提供文件打包 壓縮類庫. |
Configuration | 一個java應(yīng)用程序的配置管理類庫. |
DBCP | 提供數(shù)據(jù)庫連接池服務(wù). |
DbUtils | 提供對jdbc 的操作封裝來簡化數(shù)據(jù)查詢和記錄讀取操作. |
java發(fā)送郵件 對javamail的封裝. | |
FileUpload | 提供文件上傳功能. |
HttpClien | 提供HTTP客戶端與服務(wù)器的各種通訊操作. 現(xiàn)在已改成HttpComponents |
IO | io工具的封裝. |
Lang | Java基本對象方法的工具類包 如:StringUtils,ArrayUtils等等. |
Logging | 提供的是一個Java 的日志接口. |
Validator | 提供了客戶端和服務(wù)器端的數(shù)據(jù)驗證框架. |
1、BeanUtils 提供了對于JavaBean進行各種操作, 比如對象,屬性復(fù)制等等。
//1、 克隆對象 // 新創(chuàng)建一個普通Java Bean,用來作為被克隆的對象 public class Person { private String name = ""; private String email = ""; private int age; //省略 set,get方法 } // 再創(chuàng)建一個Test類,其中在main方法中代碼如下: import java.lang.reflect.InvocationTargetException; import java.util.HashMap; import java.util.Map; import org.apache.commons.beanutils.BeanUtils; import org.apache.commons.beanutils.ConvertUtils; public class Test { /** * @param args */ public static void main(String[] args) { Person person = new Person(); person.setName("tom"); person.setAge(21); try { //克隆 Person person2 = (Person)BeanUtils.cloneBean(person); System.out.println(person2.getName()+">>"+person2.getAge()); } catch (IllegalAccessException e) { e.printStackTrace(); } catch (InstantiationException e) { e.printStackTrace(); } catch (InvocationTargetException e) { e.printStackTrace(); } catch (NoSuchMethodException e) { e.printStackTrace(); } } } // 原理也是通過Java的反射機制來做的。 // 2、 將一個Map對象轉(zhuǎn)化為一個Bean // 這個Map對象的key必須與Bean的屬性相對應(yīng)。 Map map = new HashMap(); map.put("name","tom"); map.put("email","tom@"); map.put("age","21"); //將map轉(zhuǎn)化為一個Person對象 Person person = new Person(); BeanUtils.populate(person,map); // 通過上面的一行代碼,此時person的屬性就已經(jīng)具有了上面所賦的值了。 // 將一個Bean轉(zhuǎn)化為一個Map對象了,如下: Map map = BeanUtils.describe(person)
2、Betwixt XML與Java對象之間相互轉(zhuǎn)換。
//1、 將JavaBean轉(zhuǎn)為XML內(nèi)容 // 新創(chuàng)建一個Person類 public class Person{ private String name; private int age; /** Need to allow bean to be created via reflection */ public PersonBean() { } public PersonBean(String name, int age) { this.name = name; this.age = age; } //省略set, get方法 public String toString() { return "PersonBean[name='" + name + "',age='" + age + "']"; } } //再創(chuàng)建一個WriteApp類: import java.io.StringWriter; import org.apache.commons.betwixt.io.BeanWriter; public class WriteApp { /** * 創(chuàng)建一個例子Bean,并將它轉(zhuǎn)化為XML. */ public static final void main(String [] args) throws Exception { // 先創(chuàng)建一個StringWriter,我們將把它寫入為一個字符串 StringWriter outputWriter = new StringWriter(); // Betwixt在這里僅僅是將Bean寫入為一個片斷 // 所以如果要想完整的XML內(nèi)容,我們應(yīng)該寫入頭格式 outputWriter.write(“<?xml version='1.0′ encoding='UTF-8′ ?>\n”); // 創(chuàng)建一個BeanWriter,其將寫入到我們預(yù)備的stream中 BeanWriter beanWriter = new BeanWriter(outputWriter); // 配置betwixt // 更多詳情請參考java docs 或最新的文檔 beanWriter.getXMLIntrospector().getConfiguration().setAttributesForPrimitives(false); beanWriter.getBindingConfiguration().setMapIDs(false); beanWriter.enablePrettyPrint(); // 如果這個地方不傳入XML的根節(jié)點名,Betwixt將自己猜測是什么 // 但是讓我們將例子Bean名作為根節(jié)點吧 beanWriter.write(“person”, new PersonBean(“John Smith”, 21)); //輸出結(jié)果 System.out.println(outputWriter.toString()); // Betwixt寫的是片斷而不是一個文檔,所以不要自動的關(guān)閉掉writers或者streams, //但這里僅僅是一個例子,不會做更多事情,所以可以關(guān)掉 outputWriter.close(); } } //2、 將XML轉(zhuǎn)化為JavaBean import java.io.StringReader; import org.apache.commons.betwixt.io.BeanReader; public class ReadApp { public static final void main(String args[]) throws Exception{ // 先創(chuàng)建一個XML,由于這里僅是作為例子,所以我們硬編碼了一段XML內(nèi)容 StringReader xmlReader = new StringReader( "<?xml version='1.0′ encoding='UTF-8′ ?> <person><age>25</age><name>James Smith</name></person>"); //創(chuàng)建BeanReader BeanReader beanReader = new BeanReader(); //配置reader beanReader.getXMLIntrospector().getConfiguration().setAttributesForPrimitives(false); beanReader.getBindingConfiguration().setMapIDs(false); //注冊beans,以便betwixt知道XML將要被轉(zhuǎn)化為一個什么Bean beanReader.registerBeanClass("person", PersonBean.class); //現(xiàn)在我們對XML進行解析 PersonBean person = (PersonBean) beanReader.parse(xmlReader); //輸出結(jié)果 System.out.println(person); } }
3、Codec 提供了一些公共的編解碼實現(xiàn),比如Base64, Hex, MD5,Phonetic and URLs等等。
//Base64編解碼 private static String encodeTest(String str){ Base64 base64 = new Base64(); try { str = base64.encodeToString(str.getBytes("UTF-8")); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } System.out.println("Base64 編碼后:"+str); return str; } private static void decodeTest(String str){ Base64 base64 = new Base64(); //str = Arrays.toString(Base64.decodeBase64(str)); str = new String(Base64.decodeBase64(str)); System.out.println("Base64 解碼后:"+str); }
4、Collections 對java.util的擴展封裝,處理數(shù)據(jù)還是挺靈活的。
org.apache.commons.collections – Commons Collections自定義的一組公用的接口和工具類
org.apache.commons.collections.bag – 實現(xiàn)Bag接口的一組類
org.apache.commons.collections.bidimap – 實現(xiàn)BidiMap系列接口的一組類
org.apache.commons.collections.buffer – 實現(xiàn)Buffer接口的一組類
org.apache.commons.collections.collection – 實現(xiàn)java.util.Collection接口的一組類
org.apache.commons.collections.comparators – 實現(xiàn)java.util.Comparator接口的一組類
org.apache.commons.collections.functors – Commons Collections自定義的一組功能類
org.apache.commons.collections.iterators – 實現(xiàn)java.util.Iterator接口的一組類
org.apache.commons.collections.keyvalue – 實現(xiàn)集合和鍵/值映射相關(guān)的一組類
org.apache.commons.collections.list – 實現(xiàn)java.util.List接口的一組類
org.apache.commons.collections.map – 實現(xiàn)Map系列接口的一組類
org.apache.commons.collections.set – 實現(xiàn)Set系列接口的一組類
/** * 得到集合里按順序存放的key之后的某一Key */ OrderedMap map = new LinkedMap(); map.put("FIVE", "5"); map.put("SIX", "6"); map.put("SEVEN", "7"); map.firstKey(); // returns "FIVE" map.nextKey("FIVE"); // returns "SIX" map.nextKey("SIX"); // returns "SEVEN" /** * 通過key得到value * 通過value得到key * 將map里的key和value對調(diào) */ BidiMap bidi = new TreeBidiMap(); bidi.put("SIX", "6"); bidi.get("SIX"); // returns "6" bidi.getKey("6"); // returns "SIX" // bidi.removeValue("6"); // removes the mapping BidiMap inverse = bidi.inverseBidiMap(); // returns a map with keys and values swapped System.out.println(inverse); /** * 得到兩個集合中相同的元素 */ List<String> list1 = new ArrayList<String>(); list1.add("1"); list1.add("2"); list1.add("3"); List<String> list2 = new ArrayList<String>(); list2.add("2"); list2.add("3"); list2.add("5"); Collection c = CollectionUtils.retainAll(list1, list2); System.out.println(c);
5、Compress commons compress中的打包、壓縮類庫。
//創(chuàng)建壓縮對象 ZipArchiveEntry entry = new ZipArchiveEntry("CompressTest"); //要壓縮的文件 File f=new File("e:\\test.pdf"); FileInputStream fis=new FileInputStream(f); //輸出的對象 壓縮的文件 ZipArchiveOutputStream zipOutput=new ZipArchiveOutputStream(new File("e:\\test.zip")); zipOutput.putArchiveEntry(entry); int i=0,j; while((j=fis.read()) != -1) { zipOutput.write(j); i++; System.out.println(i); } zipOutput.closeArchiveEntry(); zipOutput.close(); fis.close();
6、Configuration 用來幫助處理配置文件的,支持很多種存儲方式。
1. Properties files
2. XML documents
3. Property list files (.plist)
4. JNDI
5. JDBC Datasource
6. System properties
7. Applet parameters
8. Servlet parameters
//舉一個Properties的簡單例子 # usergui.properties colors.background = #FFFFFF colors.foreground = #000080 window.width = 500 window.height = 300 PropertiesConfiguration config = new PropertiesConfiguration("usergui.properties"); config.setProperty("colors.background", "#000000); config.save(); config.save("usergui.backup.properties); //save a copy Integer integer = config.getInteger("window.width");
7、DBCP (Database Connection Pool)是一個依賴Jakarta commons-pool對象池機制的數(shù)據(jù)庫連接池,Tomcat的數(shù)據(jù)源使用的就是DBCP。
import javax.sql.DataSource; import java.sql.Connection; import java.sql.Statement; import java.sql.ResultSet; import java.sql.SQLException; import org.apache.commons.pool.ObjectPool; import org.apache.commons.pool.impl.GenericObjectPool; import org.apache.commons.dbcp.ConnectionFactory; import org.apache.commons.dbcp.PoolingDataSource; import org.apache.commons.dbcp.PoolableConnectionFactory; import org.apache.commons.dbcp.DriverManagerConnectionFactory; //官方示例 public class PoolingDataSources { public static void main(String[] args) { System.out.println("加載jdbc驅(qū)動"); try { Class.forName("oracle.jdbc.driver.OracleDriver"); } catch (ClassNotFoundException e) { e.printStackTrace(); } System.out.println("Done."); // System.out.println("設(shè)置數(shù)據(jù)源"); DataSource dataSource = setupDataSource("jdbc:oracle:thin:@localhost:1521:test"); System.out.println("Done."); // Connection conn = null; Statement stmt = null; ResultSet rset = null; try { System.out.println("Creating connection."); conn = dataSource.getConnection(); System.out.println("Creating statement."); stmt = conn.createStatement(); System.out.println("Executing statement."); rset = stmt.executeQuery("select * from person"); System.out.println("Results:"); int numcols = rset.getMetaData().getColumnCount(); while(rset.next()) { for (int i=0;i<=numcols;i++) { System.out.print("\t" + rset.getString(i)); } System.out.println(""); } } catch(SQLException e) { e.printStackTrace(); } finally { try { if (rset != null) rset.close(); } catch(Exception e) { } try { if (stmt != null) stmt.close(); } catch(Exception e) { } try { if (conn != null) conn.close(); } catch(Exception e) { } } } public static DataSource setupDataSource(String connectURI) { //設(shè)置連接地址 ConnectionFactory connectionFactory = new DriverManagerConnectionFactory( connectURI, null); // 創(chuàng)建連接工廠 PoolableConnectionFactory poolableConnectionFactory = new PoolableConnectionFactory( connectionFactory); //獲取GenericObjectPool 連接的實例 ObjectPool connectionPool = new GenericObjectPool( poolableConnectionFactory); // 創(chuàng)建 PoolingDriver PoolingDataSource dataSource = new PoolingDataSource(connectionPool); return dataSource; } }
8、DbUtilsApache組織提供的一個資源JDBC工具類庫,它是對JDBC的簡單封裝,對傳統(tǒng)操作數(shù)據(jù)庫的類進行二次封裝,可以把結(jié)果集轉(zhuǎn)化成List。,同時也不影響程序的性能。
DbUtils類:啟動類
ResultSetHandler接口:轉(zhuǎn)換類型接口
MapListHandler類:實現(xiàn)類,把記錄轉(zhuǎn)化成List
BeanListHandler類:實現(xiàn)類,把記錄轉(zhuǎn)化成List,使記錄為JavaBean類型的對象
QreryRunner類:執(zhí)行SQL語句的類
import org.apache.commons.dbutils.DbUtils; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.BeanListHandler; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.util.List; //轉(zhuǎn)換成list public class BeanLists { public static void main(String[] args) { Connection conn = null; String url = "jdbc:mysql://localhost:3306/ptest"; String jdbcDriver = "com.mysql.jdbc.Driver"; String user = "root"; String password = "ptest"; DbUtils.loadDriver(jdbcDriver); try { conn = DriverManager.getConnection(url, user, password); QueryRunner qr = new QueryRunner(); List results = (List) qr.query(conn, "select id,name from person", new BeanListHandler(Person.class)); for (int i = 0; i < results.size(); i++) { Person p = (Person) results.get(i); System.out.println("id:" + p.getId() + ",name:" + p.getName()); } } catch (SQLException e) { e.printStackTrace(); } finally { DbUtils.closeQuietly(conn); } } } public class Person{ private Integer id; private String name; //省略set, get方法 } import org.apache.commons.dbutils.DbUtils; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.MapListHandler; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.util.List; import java.util.Map; //轉(zhuǎn)換成map public class MapLists { public static void main(String[] args) { Connection conn = null; String url = "jdbc:mysql://localhost:3306/ptest"; String jdbcDriver = "com.mysql.jdbc.Driver"; String user = "root"; String password = "ptest"; DbUtils.loadDriver(jdbcDriver); try { conn = DriverManager.getConnection(url, user, password); QueryRunner qr = new QueryRunner(); List results = (List) qr.query(conn, "select id,name from person", new MapListHandler()); for (int i = 0; i < results.size(); i++) { Map map = (Map) results.get(i); System.out.println("id:" + map.get("id") + ",name:" + map.get("name")); } } catch (SQLException e) { e.printStackTrace(); } finally { DbUtils.closeQuietly(conn); } } }
9、Email 提供的一個開源的API,是對javamail的封裝。
//用commons email發(fā)送郵件 public static void main(String args[]){ Email email = new SimpleEmail(); email.setHostName("smtp.googlemail.com"); email.setSmtpPort(465); email.setAuthenticator(new DefaultAuthenticator("username", "password")); email.setSSLOnConnect(true); email.setFrom("user@gmail.com"); email.setSubject("TestMail"); email.setMsg("This is a test mail ... :-)"); email.addTo("foo@bar.com"); email.send(); }
10、FileUpload java web文件上傳功能。
//官方示例: //* 檢查請求是否含有上傳文件 // Check that we have a file upload request Boolean isMultipart = ServletFileUpload.isMultipartContent(request); //現(xiàn)在我們得到了items的列表 //如果你的應(yīng)用近于最簡單的情況,上面的處理就夠了。但我們有時候還是需要更多的控制。 //下面提供了幾種控制選擇: // Create a factory for disk-based file items DiskFileItemFactory factory = new DiskFileItemFactory(); // Set factory constraints factory.setSizeThreshold(yourMaxMemorySize); factory.setRepository(yourTempDirectory); // Create a new file upload handler ServletFileUpload upload = new ServletFileUpload(factory); // 設(shè)置最大上傳大小 upload.setSizeMax(yourMaxRequestSize); // 解析所有請求 List /* FileItem */ items = upload.parseRequest(request); // Create a factory for disk-based file items DiskFileItemFactory factory = new DiskFileItemFactory( yourMaxMemorySize, yourTempDirectory); //一旦解析完成,你需要進一步處理item的列表。 // Process the uploaded items Iterator iter = items.iterator(); while (iter.hasNext()) { FileItem item = (FileItem) iter.next(); if (item.isFormField()) { processFormField(item); } else { processUploadedFile(item); } } //區(qū)分數(shù)據(jù)是否為簡單的表單數(shù)據(jù),如果是簡單的數(shù)據(jù): // processFormField if (item.isFormField()) { String name = item.getFieldName(); String value = item.getString(); //...省略步驟 } //如果是提交的文件: // processUploadedFile if (!item.isFormField()) { String fieldName = item.getFieldName(); String fileName = item.getName(); String contentType = item.getContentType(); Boolean isInMemory = item.isInMemory(); long sizeInBytes = item.getSize(); //...省略步驟 } //對于這些item,我們通常要把它們寫入文件,或轉(zhuǎn)為一個流 // Process a file upload if (writeToFile) { File uploadedFile = new File(...); item.write(uploadedFile); } else { InputStream uploadedStream = item.getInputStream(); //...省略步驟 uploadedStream.close(); } //或轉(zhuǎn)為字節(jié)數(shù)組保存在內(nèi)存中: // Process a file upload in memory byte[] data = item.get(); //...省略步驟 //如果這個文件真的很大,你可能會希望向用戶報告到底傳了多少到服務(wù)端,讓用戶了解上傳的過程 //Create a progress listener ProgressListener progressListener = new ProgressListener(){ public void update(long pBytesRead, long pContentLength, int pItems) { System.out.println("We are currently reading item " + pItems); if (pContentLength == -1) { System.out.println("So far, " + pBytesRead + " bytes have been read."); } else { System.out.println("So far, " + pBytesRead + " of " + pContentLength + " bytes have been read."); } } } ; upload.setProgressListener(progressListener);
11、HttpClien 基于HttpCore實 現(xiàn)的一個HTTP/1.1兼容的HTTP客戶端,它提供了一系列可重用的客戶端身份驗證、HTTP狀態(tài)保持、HTTP連接管理module。
//GET方法 import java.io.IOException; import org.apache.commons.httpclient.*; import org.apache.commons.httpclient.methods.GetMethod; import org.apache.commons.httpclient.params.HttpMethodParams; public class GetSample{ public static void main(String[] args) { // 構(gòu)造HttpClient的實例 HttpClient httpClient = new HttpClient(); // 創(chuàng)建GET方法的實例 GetMethod getMethod = new GetMethod("http://www.ibm.com"); // 使用系統(tǒng)提供的默認的恢復(fù)策略 getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler()); try { // 執(zhí)行g(shù)etMethod int statusCode = httpClient.executeMethod(getMethod); if (statusCode != HttpStatus.SC_OK) { System.err.println("Method failed: " + getMethod.getStatusLine()); } // 讀取內(nèi)容 byte[] responseBody = getMethod.getResponseBody(); // 處理內(nèi)容 System.out.println(new String(responseBody)); } catch (HttpException e) { // 發(fā)生致命的異常,可能是協(xié)議不對或者返回的內(nèi)容有問題 System.out.println("Please check your provided http address!"); e.printStackTrace(); } catch (IOException e) { // 發(fā)生網(wǎng)絡(luò)異常 e.printStackTrace(); } finally { // 釋放連接 getMethod.releaseConnection(); } } } //POST方法 import java.io.IOException; import org.apache.commons.httpclient.*; import org.apache.commons.httpclient.methods.PostMethod; import org.apache.commons.httpclient.params.HttpMethodParams; public class PostSample{ public static void main(String[] args) { // 構(gòu)造HttpClient的實例 HttpClient httpClient = new HttpClient(); // 創(chuàng)建POST方法的實例 String url = "http://www.oracle.com/"; PostMethod postMethod = new PostMethod(url); // 填入各個表單域的值 NameValuePair[] data = { new NameValuePair("id", "youUserName"), new NameValuePair("passwd", "yourPwd") } ; // 將表單的值放入postMethod中 postMethod.setRequestBody(data); // 執(zhí)行postMethod int statusCode = httpClient.executeMethod(postMethod); // HttpClient對于要求接受后繼服務(wù)的請求,象POST和PUT等不能自動處理轉(zhuǎn)發(fā) // 301或者302 if (statusCode == HttpStatus.SC_MOVED_PERMANENTLY || statusCode == HttpStatus.SC_MOVED_TEMPORARILY) { // 從頭中取出轉(zhuǎn)向的地址 Header locationHeader = postMethod.getResponseHeader("location"); String location = null; if (locationHeader != null) { location = locationHeader.getValue(); System.out.println("The page was redirected to:" + location); } else { System.err.println("Location field value is null."); } return; } } }
12、IO 對java.io的擴展 操作文件非常方便。
//1.讀取Stream //標準代碼: InputStream in = new URL( "http://jakarta.apache.org" ).openStream(); try { InputStreamReader inR = new InputStreamReader( in ); BufferedReader buf = new BufferedReader( inR ); String line; while ( ( line = buf.readLine() ) != null ) { System.out.println( line ); } } finally { in.close(); } //使用IOUtils InputStream in = new URL( "http://jakarta.apache.org" ).openStream(); try { System.out.println( IOUtils.toString( in ) ); } finally { IOUtils.closeQuietly(in); } //2.讀取文件 File file = new File("/commons/io/project.properties"); List lines = FileUtils.readLines(file, "UTF-8"); //3.察看剩余空間 long freeSpace = FileSystemUtils.freeSpace("C:/");
13、Lang 主要是一些公共的工具集合,比如對字符、數(shù)組的操作等等。
// 1 合并兩個數(shù)組: org.apache.commons.lang. ArrayUtils // 有時我們需要將兩個數(shù)組合并為一個數(shù)組,用ArrayUtils就非常方便,示例如下: private static void testArr() { String[] s1 = new String[] { "1", "2", "3" }; String[] s2 = new String[] { "a", "b", "c" }; String[] s = (String[]) ArrayUtils.addAll(s1, s2); for (int i = 0; i < s.length; i++) { System.out.println(s[i]); } String str = ArrayUtils.toString(s); str = str.substring(1, str.length() - 1); System.out.println(str + ">>" + str.length()); } //2 截取從from開始字符串 StringUtils.substringAfter("SELECT * FROM PERSON ", "from"); //3 判斷該字符串是不是為數(shù)字(0~9)組成,如果是,返回true 但該方法不識別有小數(shù)點和 請注意 StringUtils.isNumeric("454534"); //返回true //4.取得類名 System.out.println(ClassUtils.getShortClassName(Test.class)); //取得其包名 System.out.println(ClassUtils.getPackageName(Test.class)); //5.NumberUtils System.out.println(NumberUtils.stringToint("6")); //6.五位的隨機字母和數(shù)字 System.out.println(RandomStringUtils.randomAlphanumeric(5)); //7.StringEscapeUtils System.out.println(StringEscapeUtils.escapeHtml("<html>")); //輸出結(jié)果為<html> System.out.println(StringEscapeUtils.escapeJava("String")); //8.StringUtils,判斷是否是空格字符 System.out.println(StringUtils.isBlank(" ")); //將數(shù)組中的內(nèi)容以,分隔 System.out.println(StringUtils.join(test,",")); //在右邊加下字符,使之總長度為6 System.out.println(StringUtils.rightPad("abc", 6, 'T')); //首字母大寫 System.out.println(StringUtils.capitalize("abc")); //Deletes all whitespaces from a String 刪除所有空格 System.out.println( StringUtils.deleteWhitespace(" ab c ")); //判斷是否包含這個字符 System.out.println( StringUtils.contains("abc", "ba")); //表示左邊兩個字符 System.out.println( StringUtils.left("abc", 2)); System.out.println(NumberUtils.stringToint("33"));
14、Logging 提供的是一個Java 的日志接口,同時兼顧輕量級和不依賴于具體的日志實現(xiàn)工具。
import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class CommonLogTest { private static Log log = LogFactory.getLog(CommonLogTest.class); //日志打印 public static void main(String[] args) { log.error("ERROR"); log.debug("DEBUG"); log.warn("WARN"); log.info("INFO"); log.trace("TRACE"); System.out.println(log.getClass()); } }
15、Validator 通用驗證系統(tǒng),該組件提供了客戶端和服務(wù)器端的數(shù)據(jù)驗證框架。
驗證日期
// 獲取日期驗證 DateValidator validator = DateValidator.getInstance(); // 驗證/轉(zhuǎn)換日期 Date fooDate = validator.validate(fooString, "dd/MM/yyyy"); if (fooDate == null) { // 錯誤 不是日期 return; }
表達式驗證
// 設(shè)置參數(shù) Boolean caseSensitive = false; String regex1 = "^([A-Z]*)(?:\\-)([A-Z]*)*$" String regex2 = "^([A-Z]*)$"; String[] regexs = new String[] {regex1, regex1}; // 創(chuàng)建驗證 RegexValidator validator = new RegexValidator(regexs, caseSensitive); // 驗證返回boolean Boolean valid = validator.isValid("abc-def"); // 驗證返回字符串 String result = validator.validate("abc-def"); // 驗證返回數(shù)組 String[] groups = validator.match("abc-def");
配置文件中使用驗證
<form-validation> <global> <validator name="required" classname="org.apache.commons.validator.TestValidator" method="validateRequired" methodParams="java.lang.Object, org.apache.commons.validator.Field"/> </global> <formset> </formset> </form-validation> 添加姓名驗證. <form-validation> <global> <validator name="required" classname="org.apache.commons.validator.TestValidator" method="validateRequired" methodParams="java.lang.Object, org.apache.commons.validator.Field"/> </global> <formset> <form name="nameForm"> <field property="firstName" depends="required"> <arg0 key="nameForm.firstname.displayname"/> </field> <field property="lastName" depends="required"> <arg0 key="nameForm.lastname.displayname"/> </field> </form> </formset> </form-validation>
驗證類
Excerpts from org.apache.commons.validator.RequiredNameTest //加載驗證配置文件 InputStream in = this.getClass().getResourceAsStream("validator-name-required.xml"); ValidatorResources resources = new ValidatorResources(in); //這個是自己創(chuàng)建的bean 我這里省略了 Name name = new Name(); Validator validator = new Validator(resources, "nameForm"); //設(shè)置參數(shù) validator.setParameter(Validator.BEAN_PARAM, name); Map results = null; //驗證 results = validator.validate(); if (results.get("firstName") == null) { //驗證成功 } else { //有錯誤 int errors = ((Integer)results.get("firstName")).intValue(); }
總結(jié)
以上就是本文關(guān)于apache commons工具集代碼詳解的全部內(nèi)容,希望對大家有所幫助。感興趣的朋友可以繼續(xù)參閱本站其他相關(guān)專題,如有不足之處,歡迎留言指出。感謝朋友們對本站的支持!
免責聲明:本站發(fā)布的內(nèi)容(圖片、視頻和文字)以原創(chuàng)、轉(zhuǎn)載和分享為主,文章觀點不代表本網(wǎng)站立場,如果涉及侵權(quán)請聯(lián)系站長郵箱:is@yisu.com進行舉報,并提供相關(guān)證據(jù),一經(jīng)查實,將立刻刪除涉嫌侵權(quán)內(nèi)容。