spring消息轉(zhuǎn)換器使用詳解

更新時(shí)間：2017年07月05日 11:56:15 作者：wdx330616

這篇文章主要為大家詳細(xì)介紹了spring消息轉(zhuǎn)換器的使用，具有一定的參考價(jià)值，感興趣的小伙伴們可以參考一下

本文實(shí)例為大家分享了spring消息轉(zhuǎn)換器的具體代碼，供大家參考，具體內(nèi)容如下

//domain

package com.crazy.goods.tools;
/**
 * 0755-351512
 * @author Administrator
 *
 */
public class Phone {
  private String qno;
  private String number;
  public String getQno() {
    return qno;
  }
  public void setQno(String qno) {
    this.qno = qno;
  }
  public String getNumber() {
    return number;
  }
  public void setNumber(String number) {
    this.number = number;
  }
  
}

//消息轉(zhuǎn)換器要實(shí)現(xiàn)一個(gè)抽象類AbstractHttpMessageConverter

package com.crazy.goods.tools;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.HttpMessageNotWritableException;

public class MyMessageConvertor extends AbstractHttpMessageConverter<Phone> {

  /**
   * 將請(qǐng)求頭數(shù)據(jù)轉(zhuǎn)換成Phone
   */
  
  @Override
  protected Phone readInternal(Class<? extends Phone> arg0,
      HttpInputMessage msg) throws IOException,
      HttpMessageNotReadableException {
    //參數(shù)必須使用post提交必須在body中
    InputStream is=msg.getBody();
    BufferedReader br=new BufferedReader(new InputStreamReader(is));
    String param=br.readLine();
    String phone=param.split("=")[1];
    Phone phoneObj=new Phone();
    phoneObj.setQno(phone.split("-")[0]);
    phoneObj.setNumber(phone.split("-")[1]);
    return phoneObj;
  }
  /**
   * 當(dāng)前的轉(zhuǎn)換器支持轉(zhuǎn)換的類
   */
  @Override
  protected boolean supports(Class<?> arg0) {
    if(arg0==Phone.class){
      return true;
    }
    return false;
  }
  /**
   * 用于將返回的對(duì)象轉(zhuǎn)換成字符串顯示在網(wǎng)頁
   */
  @Override
  protected void writeInternal(Phone phone, HttpOutputMessage arg1)
      throws IOException, HttpMessageNotWritableException {
    String p=phone.getQno()+"-"+phone.getNumber();
    arg1.getBody().write(p.getBytes("UTF-8"));
  }

}

//springmvc.xml 要配置bean：消息轉(zhuǎn)換器，只有post提交方式才會(huì)被轉(zhuǎn)換器攔截

<?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:context="http://www.springframework.org/schema/context"
  xmlns:tx="http://www.springframework.org/schema/tx"
  xmlns:aop="http://www.springframework.org/schema/aop"
  xmlns:mvc="http://www.springframework.org/schema/mvc"
  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
      http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
    ">
  <!--springmvc只能掃描控制層 -->
  <context:component-scan base-package="com.crazy.goods">
    <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service"/>
    <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Repository"/>
  </context:component-scan>
  
  <!--消息轉(zhuǎn)換器 必須使用post提交  -->
  <mvc:annotation-driven>
    <mvc:message-converters>
      <bean class="com.crazy.goods.tools.MyMessageConvertor">
        <property name="supportedMediaTypes">
          <list>
            <value>text/html;charset=UTF-8</value>
             <value>application/x-www-form-urlencoded</value>
          </list>
        </property>
      </bean>
    </mvc:message-converters>
  </mvc:annotation-driven>
</beans>

servlet測試

package com.crazy.goods.servlet;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;

import com.crazy.goods.tools.Phone;

/**
* @author Administrator
* 創(chuàng)建時(shí)間：2017年7月1日下午3:11:27
*/
@Controller
public class ReservePageServelt {

// /**
// * forward:轉(zhuǎn)發(fā)
// * redirect:重定向
// * @param req
// * @param resp
// * @return
// * @throws ServletException
// * @throws IOException
// */
// @RequestMapping(value="/add",method={RequestMethod.GET})
// public String doGet(HttpServletRequest req, HttpServletResponse resp/*,@PathVariable("testid") String testid*/) throws ServletException, IOException {
// req.getRequestDispatcher("/reversegood.jsp").forward(req, resp);
// return "/reversegood.jsp";
// resp.getWriter().print(testid);
// }


//消息轉(zhuǎn)換器思路，

//原理就是將請(qǐng)求體或者請(qǐng)求頭的數(shù)據(jù)轉(zhuǎn)換為action方法的參數(shù)，同時(shí)將方法的返回值的內(nèi)容轉(zhuǎn)換為響應(yīng)頭
//當(dāng)url路徑訪問過來時(shí)，看到使用了@RequestBody注解，這個(gè)注解標(biāo)識(shí)這個(gè)類要被消息轉(zhuǎn)換器處理，就會(huì)springmvcxml文件中讀到消息轉(zhuǎn)換器，然后進(jìn)入supports方法
//判斷這個(gè)類是否被指定的轉(zhuǎn)換器支持，如果支持，就調(diào)用readInternal方法，進(jìn)行切割，然后將值傳遞到對(duì)象中,處理完成為對(duì)象之后，就會(huì)調(diào)用writeInternal轉(zhuǎn)換為響應(yīng)頭
@RequestMapping(value="/add")
@ResponseBody
public Phone messageConvertor( @RequestBody Phone phone,HttpServletResponse response) {
System.out.println(phone.getQno()+phone.getNumber());
return phone;

}

}

總結(jié)：消息轉(zhuǎn)換器的原理就是，自定義將請(qǐng)求體的數(shù)據(jù)轉(zhuǎn)換為形參（對(duì)象），然后將方法的返回值內(nèi)容轉(zhuǎn)換為響應(yīng)頭

步驟：

當(dāng)url路徑訪問過來時(shí)，看到使用了@RequestBody注解，這個(gè)注解標(biāo)識(shí)這個(gè)類要被消息轉(zhuǎn)換器處理，就會(huì)springmvcxml文件中讀到消息轉(zhuǎn)換器，然后進(jìn)入supports方法
判斷這個(gè)類是否被指定的轉(zhuǎn)換器支持，如果支持，就調(diào)用readInternal方法，進(jìn)行切割，然后將值傳遞到對(duì)象中.

處理完成為對(duì)象之后，就會(huì)調(diào)用writeInternal轉(zhuǎn)換為響應(yīng)頭

以上就是本文的全部內(nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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