JSon_零基础_004_将Set集合对象转换为JSon格式的对象字符串，返回给界面

浏览数：22 / 时间：2015年06月09日

将Set集合对象转换为JSon格式的对象字符串，返回给界面

需要导入的jar包：

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编写：servlet:

package com.west.webcourse.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

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

import net.sf.json.JSONArray;

public class JavaBeanToJOSNString extends HttpServlet {

    /** 第02步：重写doGet()方法,下一步：测试 */
    @Override
    protected void doGet(HttpServletRequest request,
            HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html;charset=utf-8");
        PrintWriter out = response.getWriter();
        System.out.println("转换");
        out.print("转换后的JSON字符串：");
        /** 向浏览器发送JSon格式的字符串 */
        out.print(getSetToJsonString());
        out.flush();
        out.close();
    }

    /** 第01步：创建JSon格式字符串转换方法:将Set集合转换成json类型字符串 */
    public String getSetToJsonString() {
        Set set=new HashSet();
        set.add(Boolean.TRUE);
        set.add(new Integer(1));
        set.add(new String[]{"zhang3","li4","wang5"});
        set.add("function(arrayIndex){return this.arrayType[arrayIndex];}");
        JSONArray setToJsonArray=new JSONArray().fromObject(set);
        System.out
                .println("com.west.webcourse.servlet.JavaBeanToJOSNString.java::"
                        + setToJsonArray);
        return setToJsonArray.toString();
    }
}

测试servlet：

package com.west.webcourse.servlet;
/**
 * 第03步：测试
 * 下一步：配置web.xml
 */
import org.junit.BeforeClass;
import org.junit.Test;

public class JavaBeanToJOSNStringTest {
    static JavaBeanToJOSNString js;
    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
        js=new JavaBeanToJOSNString();
    }

    @Test
    public void testToJsonString() {
        js.getSetToJsonString();
    }

}

配置web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <display-name></display-name>
    <!-- 第04步：配置servlet,下一步：personinfo.jsp -->
    <servlet>
        <description>This</description>
        <display-name>This</display-name>
        <servlet-name>JavaBeanToJOSNString</servlet-name>
        <servlet-class>com.west.webcourse.servlet.JavaBeanToJOSNString</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>JavaBeanToJOSNString</servlet-name>
        <url-pattern>/javaBeanToJOSNString</url-pattern>
    </servlet-mapping>

    <welcome-file-list>
        <welcome-file>personinfo.jsp</welcome-file>
    </welcome-file-list>
</web-app>

编写界面：personinfo.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
    String path = request.getContextPath();
    String basePath = request.getScheme() + "://"
            + request.getServerName() + ":" + request.getServerPort()
            + path + "/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">

<title>My JSP ‘personinfo.jsp‘ starting page</title>

<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

</head>

<body>
    <!-- 第05步：编写界面 -->
    动态获得当前项目的ContextPath所对应的目录：${pageContext.request.contextPath}
    <br>
    <a href="javaBeanToJOSNString">向servlet发送请求</a>
    <br>
</body>
</html>