将数据以json形式响应给前端

  <!-- JSON start-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.12.6</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.12.6</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.12.6</version>
        </dependency>
        <!-- JSON end  -->

package com.bh.po;

public class User {
    private String username;
    private String password;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

package com.bh.controller;

import com.bh.po.User;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

import java.util.ArrayList;
import java.util.List;
@Controller
public class JsonController {

//@ResponseBody注解的作用就是将数据转成json格式响应给前端

@RequestMapping("/json2.do")
public @ResponseBody List<User> getResult1() {
    List<User> list = new ArrayList<>();
    for (int i = 0; i < 10; i++) {
        User u = new User();
        u.setUsername("name_" + i);
        u.setPassword("pwd_" + i);

        list.add(u);
    }

    return list;
}
}

[
	{
		"username":"name_0",
		"password":"pwd_0"
	},
	{
		"username":"name_1",
		"password":"pwd_1"
	},
	{
		"username":"name_2",
		"password":"pwd_2"
	},
	{
		"username":"name_3",
		"password":"pwd_3"
	},
	{
		"username":"name_4",
		"password":"pwd_4"
	},
	{
		"username":"name_5",
		"password":"pwd_5"
	},
	{
		"username":"name_6",
		"password":"pwd_6"
	},
	{
		"username":"name_7",
		"password":"pwd_7"
	},
	{
		"username":"name_8",
		"password":"pwd_8"
	},
	{
		"username":"name_9",
		"password":"pwd_9"
	}]