您好,登錄后才能下訂單哦!
本篇內(nèi)容介紹了“spring怎么自定義屬性”的有關(guān)知識(shí),在實(shí)際案例的操作過程中,不少人都會(huì)遇到這樣的困境,接下來就讓小編帶領(lǐng)大家學(xué)習(xí)一下如何處理這些情況吧!希望大家仔細(xì)閱讀,能夠?qū)W有所成!
在開發(fā)Dubbo應(yīng)用的時(shí)候,我們會(huì)在xml中做以下類似的配置:
<dubbo:application name="dubbo_service_provider" /> <dubbo:registry address="zookeeper://127.0.0.1:2181" /> <dubbo:protocol name="dubbo" port="20880" />
spring啟動(dòng)后,Dubbo的本地運(yùn)行時(shí)環(huán)境就會(huì)獲取到這些信息,根據(jù)這些信息完成注冊(cè)服務(wù),今天我們實(shí)戰(zhàn)的內(nèi)容就是開發(fā)一個(gè)類似的自定義屬性,然后在spring項(xiàng)目中使用這個(gè)屬性;
整個(gè)實(shí)戰(zhàn)過程分為以下幾步:
創(chuàng)建web工程;
創(chuàng)建配置屬性的bean;
創(chuàng)建XSD文件;
創(chuàng)建自定義BeanDefinitionParser,制定配置信息的解析規(guī)則;
創(chuàng)建自定義NamespaceHandler,規(guī)定配置信息的解析器;
添加spring.handlers文件;
添加spring.schemas文件;
在工程中配置一個(gè)這樣的屬性;
啟動(dòng)web工程,驗(yàn)證配置;
如果您不打算編碼,也可以在GitHub下載本次實(shí)戰(zhàn)的源碼,地址是:https://github.com/zq2599/blog_demos ,里面有多個(gè)工程,本次用到的是springschemademo,如下圖紅框所示:
接下來開始實(shí)戰(zhàn):
創(chuàng)建一個(gè)maven工程,pom.xml的內(nèi)容如下,主要是把spring相關(guān)的依賴引入:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.bolingcavalry</groupId> <artifactId>springschemademo</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>app Maven Webapp</name> <url>http://maven.apache.org</url> <properties> <!-- spring版本號(hào) --> <spring.version>4.0.2.RELEASE</spring.version> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <!-- 表示開發(fā)的時(shí)候引入,發(fā)布的時(shí)候不會(huì)加載此包 --> <scope>test</scope> </dependency> <!-- spring核心包 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-oxm</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-tx</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>${spring.version}</version> </dependency> <!-- 導(dǎo)入java ee jar 包 --> <dependency> <groupId>javax</groupId> <artifactId>javaee-api</artifactId> <version>7.0</version> </dependency> <!-- JSTL標(biāo)簽類 --> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!-- 映入JSON --> <dependency> <groupId>org.codehaus.jackson</groupId> <artifactId>jackson-mapper-asl</artifactId> <version>1.9.13</version> </dependency> <!-- 上傳組件包 --> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.1</version> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.4</version> </dependency> <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.9</version> </dependency> </dependencies> <build> <finalName>${project.artifactId}</finalName> <resources> <resource> <directory>src/main/java</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> </includes> <!-- 是否替換資源中的屬性--> <filtering>false</filtering> </resource> <resource> <directory>src/main/resources</directory> </resource> </resources> <plugins> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat7-maven-plugin</artifactId> <version>2.2</version> <configuration> <url>http://localhost:8080/manager/text</url> <server>tomcat7</server> <path>/${project.artifactId}</path> <update>true</update> </configuration> </plugin> </plugins> </build> </project>
web.xml中加上spring mvc的配置:
<servlet> <servlet-name>SpringMVC</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring-mvc.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> <async-supported>true</async-supported> </servlet> <servlet-mapping> <servlet-name>SpringMVC</servlet-name> <!-- 此處可以可以配置成*.do,對(duì)應(yīng)struts的后綴習(xí)慣 --> <url-pattern>/</url-pattern> </servlet-mapping>
還有spring的配置文件,加上注解相關(guān)的配置:
<!-- 啟動(dòng)SpringMVC的注解功能,完成請(qǐng)求和注解POJO的映射 --> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"> <property name="messageConverters"> <list> <!-- JSON轉(zhuǎn)換器 --> <ref bean="mappingJacksonHttpMessageConverter" /> </list> </property> </bean>
其余的配置可以自行設(shè)置,或者參考我上傳到git上的源碼;
本次實(shí)戰(zhàn)的示例,以"電腦"為例,有兩個(gè)屬性:操作系統(tǒng)和內(nèi)存大小,如下:
package com.bolingcavalry; /** * Description: * * @author willzhao * @email zq2599@gmail.com * @date 2017/7/1 22:15 */ public class Computer { /** * 操作系統(tǒng) */ private String os; /** * 內(nèi)存大小 */ private int ram; public String getOs() { return os; } public void setOs(String os) { this.os = os; } public int getRam() { return ram; } public void setRam(int ram) { this.ram = ram; } }
在工程的src\main\resources\META-INF\computer.xsd目錄下創(chuàng)建computer.xsd文件,內(nèi)容如下:
<?xml version="1.0" encoding="UTF-8"?> <xsd:schema xmlns="http://blog.csdn.net/boling_cavalry/schema/computer" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:beans="http://www.springframework.org/schema/beans" targetNamespace="http://blog.csdn.net/boling_cavalry/schema/computer" elementFormDefault="qualified" attributeFormDefault="unqualified"> <xsd:import namespace="http://www.springframework.org/schema/beans"/> <xsd:element name="computer"> <xsd:complexType> <xsd:complexContent> <xsd:extension base="beans:identifiedType"> <xsd:attribute name="os" type="xsd:string"/> <xsd:attribute name="ram" type="xsd:int"/> </xsd:extension> </xsd:complexContent> </xsd:complexType> </xsd:element> </xsd:schema>
注意xmlns和targetNamespace的內(nèi)容,在外部使用時(shí)也會(huì)用到,還有就是xsd:element節(jié)點(diǎn),里面對(duì)computer的兩個(gè)屬性做了約束;
接下來要寫個(gè)BeanDefinitionParser,作用是拿到xml中的computer節(jié)點(diǎn)后,該如何從這個(gè)節(jié)點(diǎn)中取得有效的信息給spring環(huán)境,源碼如下:
public class ComputerBeanDefinitionParser extends AbstractSingleBeanDefinitionParser { @Override protected Class<?> getBeanClass(Element element) { return Computer.class; } @Override protected void doParse(Element element, BeanDefinitionBuilder builder) { String os = element.getAttribute("os"); String ramStr = element.getAttribute("ram"); if(StringUtils.hasText(os)){ builder.addPropertyValue("os", os); } if(StringUtils.hasText(ramStr)){ builder.addPropertyValue("ram", Integer.valueOf(ramStr)); } } }
getBeanClass方法決定了解析節(jié)點(diǎn)后返回的bean的類型; doParse方法的入?yún)⒅惺盏搅薱omputer節(jié)點(diǎn),在方法中解析"os"和"ram"兩個(gè)節(jié)點(diǎn),然后調(diào)用builder.addPropertyValue可以把解析結(jié)果傳入builder中;
自定義的NamespaceHandler,可以告訴spring環(huán)境,遇到computer的配置信息后,應(yīng)該用ComputerBeanDefinitionParser去解析,代碼很少,如下:
public class ComputerNamespaceHandler extends NamespaceHandlerSupport { public void init() { registerBeanDefinitionParser("computer", new ComputerBeanDefinitionParser()); } }
在src\main\resources\META-INF\目錄下,添加spring.handlers文件,內(nèi)容只有一行,如下:
http\://blog.csdn.net/boling_cavalry/schema/computer=com.bolingcavalry.ComputerNamespaceHandler
在src\main\resources\META-INF\目錄下,添加spring.schemas文件,內(nèi)容只有一行,如下:
http\://blog.csdn.net/boling_cavalry/schema/computer.xsd=META-INF/computer.xsd
準(zhǔn)備得差不多了,可以驗(yàn)證一下啦,在spring的配置文件中,如果要用到這個(gè)屬性,可以按照如下方式來寫:
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:bolingcavalry="http://blog.csdn.net/boling_cavalry/schema/computer" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd http://blog.csdn.net/boling_cavalry/schema/computer http://blog.csdn.net/boling_cavalry/schema/computer.xsd"> <bolingcavalry:computer id="computer" os="centos" ram="8" /> </beans>
除了bolingcavalry:computer的配置,還要注意xmlns:bolingcavalry的配置,還有xsi:schemaLocation中“http://blog.csdn.net/boling_cavalry/schema/computer"和 "http://blog.csdn.net/boling_cavalry/schema/computer.xsd” 也不要遺漏。
為了驗(yàn)證配置是生效的,我們寫一個(gè)controller在瀏覽器中顯示配置信息,代碼如下:
@Controller public class HelloController { private static SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); @Autowired Computer computer; @RequestMapping("/hello") @ResponseBody public String toIndex(HttpServletRequest request, Model model) { return "hello 001 [" + sdf.format(new Date()) + "], computer os [" + computer.getOs() + "], ram [" + computer.getRam() + "]"; } }
computer提供autowire注入,在web響應(yīng)的時(shí)候會(huì)輸出它的兩個(gè)屬性,現(xiàn)在啟動(dòng)tomcat并部署這個(gè)webapp,在瀏覽器中輸入http://localhost:8080/springschemademo/hello, 就能看到如下輸出:
“spring怎么自定義屬性”的內(nèi)容就介紹到這里了,感謝大家的閱讀。如果想了解更多行業(yè)相關(guān)的知識(shí)可以關(guān)注億速云網(wǎng)站,小編將為大家輸出更多高質(zhì)量的實(shí)用文章!
免責(zé)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(diǎn)不代表本網(wǎng)站立場(chǎng),如果涉及侵權(quán)請(qǐng)聯(lián)系站長(zhǎng)郵箱:is@yisu.com進(jìn)行舉報(bào),并提供相關(guān)證據(jù),一經(jīng)查實(shí),將立刻刪除涉嫌侵權(quán)內(nèi)容。