详解Spring MVC4 纯注解配置教程

阅读本文需要又一定的sping基础，最起码要成功的运行过一个springmvc项目。

在传统的spring项目中，我们要写一堆的xml文件。而这些xml文件格式要求又很严格，很不便于开发。而网上所谓的0配置，并不是纯粹的0配置，还是要写一些xml配置，只是用了几个@service，@controller注解而已。

在这里，我讲介绍一种新的配置方式，一行xml代码都不需要，什么web.xml,application-context.xml，beans.xml，统统去死吧！

首先建立一个maven项目，packageing方式为war，项目结构为标准maven webapp结构。

pom文件如下（很多依赖都没用，懒得去掉了）： 

<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.csonezp</groupid>
  <artifactid>springdemo</artifactid>
  <packaging>war</packaging>
  <version>1.0-snapshot</version>
  <name>dataplatform maven webapp</name>
  <url>http://maven.apache.org</url>
  <properties>
    <spring.version>4.0.1.release</spring.version>
  </properties>
  <dependencies>
    <dependency>
      <groupid>junit</groupid>
      <artifactid>junit</artifactid>
      <version>4.11</version>
    </dependency>

    <!-- spring dependencies -->
    <dependency>
      <groupid>asm</groupid>
      <artifactid>asm-commons</artifactid>
      <version>2.2.3</version>
    </dependency>
    <dependency>
      <groupid>asm</groupid>
      <artifactid>asm</artifactid>
      <version>2.2.3</version>
    </dependency>
    <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-orm</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-context</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-expression</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-tx</artifactid>
      <version>${spring.version}</version>
    </dependency>
    <dependency>
      <groupid>org.springframework</groupid>
      <artifactid>spring-webmvc</artifactid>
      <version>${spring.version}</version>
    </dependency>


    <dependency>
      <groupid>cglib</groupid>
      <artifactid>cglib</artifactid>
      <version>2.2.2</version>
    </dependency>
    <!-- servlet api, jstl -->
    <dependency>
      <groupid>javax.servlet</groupid>
      <artifactid>javax.servlet-api</artifactid>
      <version>3.0.1</version>
      <scope>provided</scope>
    </dependency>
    <dependency>
      <groupid>jstl</groupid>
      <artifactid>jstl</artifactid>
      <version>1.2</version>
    </dependency>

    <dependency>
      <groupid>org.codehaus.jackson</groupid>
      <artifactid>jackson-core-asl</artifactid>
      <version>1.8.4</version>
    </dependency>

    <dependency>
      <groupid>org.codehaus.jackson</groupid>
      <artifactid>jackson-mapper-asl</artifactid>
      <version>1.8.4</version>
    </dependency>

    <dependency>
      <groupid>c3p0</groupid>
      <artifactid>c3p0</artifactid>
      <version>0.9.1.2</version>
    </dependency>


    <dependency>
      <groupid>log4j</groupid>
      <artifactid>log4j</artifactid>
      <version>1.2.8</version>
    </dependency>


    <dependency>
      <groupid>org.json</groupid>
      <artifactid>json</artifactid>
      <version>20090211</version>
    </dependency>


    <dependency>
      <groupid>mysql</groupid>
      <artifactid>mysql-connector-java</artifactid>
      <version>5.1.6</version>
    </dependency>

    <dependency>
      <groupid>spy</groupid>
      <artifactid>spymemcached</artifactid>
      <version>2.6</version>
    </dependency>

    <dependency>
      <groupid>org.slf4j</groupid>
      <artifactid>slf4j-api</artifactid>
      <version>1.6.6</version>
    </dependency>
  </dependencies>
  <build>
    <finalname>dataplatform</finalname>
  </build>
</project>

这个时候，就该进行spring配置了。按传统方式来的话，首先要去web.xml写一堆配置，然后建立个管理beab的beans.xml，管理spring mvc 的xml，再写一坨一坨bean。就是先进一点的（也就是很多人说的0配置），也就是自己的业务bean不用写进xml了，还是很麻烦。

而我这里讲的方式，则是完全不修改任何web.xml代码，不写一行xml代码的方式。

 首先，在项目立建立一个config.java文件：

/**
 * created by zhangpeng on 16-3-22.
 * 取代beans.xml，纯注解配置各种bean
 */
@configuration
@componentscan("com.csonezp")
@enablewebmvc
public class config {
  /**
   * jsp视图解析器的bean
   * @return
   */
  @bean
  public urlbasedviewresolver setupviewresolver() {
    urlbasedviewresolver resolver = new urlbasedviewresolver();
    resolver.setprefix("/web-inf/");
    resolver.setsuffix(".jsp");
    resolver.setviewclass(jstlview.class);
    return resolver;
  }

  /**
   * 配置数据源
   * @return
   */
  @bean(name = "datasource")
  public combopooleddatasource getdatasource() {
    try {

      combopooleddatasource datasource = new combopooleddatasource();
      datasource.setjdbcurl("jdbc:mysql://localhost:3306/mfdb");
      datasource.setdriverclass("com.mysql.jdbc.driver");
      datasource.setuser("root");
      datasource.setpassword("zp1228");
      datasource.setmaxpoolsize(75);
      return datasource;
    } catch (exception e) {
      return null;
    }
  }
}

@configuration注解就是告诉spring这个是一个配置文件类，这里配置的bean要交给spring去管理。这个就是用来取代beans.xml这种文件的。

@componentscan("com.csonezp")这个注解就是配置包扫描用的，不必多说了

@enablewebmvc ，启用spring mvc支持

这里面配置了两个bean，第一个就是jsp的视图解析器，第二个则是配置了一个数据源。这些都可以对应到xml文件里面去的。找一个传统spring项目，用xml文件对比着我这个类去看，会对这种配置方式有更深的了解。

下面要建立一个webinitializer类继承webapplicationinitializer，在这里添加一个servlet。这一步是用来取代在web.xml中添加servlet的步骤

import org.springframework.web.webapplicationinitializer;
import org.springframework.web.context.support.annotationconfigwebapplicationcontext;
import org.springframework.web.servlet.dispatcherservlet;

import javax.servlet.servletcontext;
import javax.servlet.servletexception;
import javax.servlet.servletregistration.dynamic;

public class webinitializer implements webapplicationinitializer {

  public void onstartup(servletcontext servletcontext) throws servletexception {
     
    annotationconfigwebapplicationcontext ctx = new annotationconfigwebapplicationcontext();
    ctx.register(config.class); 
    ctx.setservletcontext(servletcontext);  
    
    dynamic servlet = servletcontext.addservlet("dispatcher", new dispatcherservlet(ctx));
    servlet.addmapping("/"); 
    servlet.setloadonstartup(1); 
     
  } 

}

这样就ok啦！让我们写一些代码来测试一下吧！ 

import org.springframework.stereotype.service;

/**
 * created by zhangpeng on 16-3-22.
 */
@service
public class helloservice {
  public string gethello(string name) {
    return name + ",hello!";
  }
}

import com.guduo.dataplatform.service.helloservice;
import com.guduo.dataplatform.service.movieservice;
import org.springframework.beans.factory.annotation.autowired;
import org.springframework.stereotype.controller;
import org.springframework.ui.modelmap;
import org.springframework.web.bind.annotation.requestmapping;
import org.springframework.web.bind.annotation.requestparam;

/**
 * created by zhangpeng on 16-3-22.
 */
@controller
@requestmapping("/test")
public class testcontroller {

  @autowired
  helloservice helloservice;
  @autowired
  movieservice movieservice;


  @requestmapping("/hello")
  public string sayhello(@requestparam("name") string name, modelmap model) {
    model.put("hello", helloservice.gethello(name));
    return "hello";
  }
}

一个service，一个controller。

启动项目，在浏览器中输入地址http://localhost:8080/dp/test/hello?name=sss

页面显示sss,hello!

完工！

额，忘了演示confgig里配置的bean如何使用了。其实和xml里的一样。这里拿一个dao做演示吧，这里就注入了我们在config里配置的那个数据源

@repository
public class movieplayincdao {
  private datasource datasource;

  private jdbctemplate jdbctemplateobject;

  @autowired
  public void setdatasource(datasource datasource) {
    this.datasource = datasource;
    this.jdbctemplateobject = new jdbctemplate(datasource);
  }

  public list<movieplayincreament> getmovieplayinc(int movieid) {
    try {
      string sql = "select * from movieplayincreament where movieid=?";
      list<movieplayincreament> list = jdbctemplateobject.query(sql, new movieplayincmapper(), new object[]{movieid});
      return list;
    } catch (exception e) {
      return null;
    }
  }


}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。