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

时间：2022-10-04 07:05:32

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：

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

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());

        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="">

<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>

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