java拼接JSON数据返回给前端

Question

        "mid": 0,
        "rolename": "超级管理员",
        "menuname": "one"
    },
    {
        "mid": 0,
        "rolename": "超级管理员",
        "menuname": "two"
    },
    {
        "mid": 0,
        "rolename": "超级管理员",
        "menuname": "three"
    },
    {
        "mid": 0,
        "rolename": "管理员",
        "menuname": "one"
    },
    {
        "mid": 0,
        "rolename": "管理员",
        "menuname": "two"
    },
    {
        "mid": 0,
        "rolename": "普通用户",
        "menuname": "one"
    }
],

拼接后

        "mid": 0,
        "rolename": "超级管理员",
        "menuname": "one,two,three"
    },
  
    {
        "mid": 0,
        "rolename": "管理员",
        "menuname": "one,two"
    },
    {
    {
        "mid": 0,
        "rolename": "普通用户",
        "menuname": "one"
    }
],

Answer 1

返回给前端再在前端拼接

    const arr = [
      { mid: 0, rolename: "超级管理员", menuname: "one" },
      {
        mid: 0,
        rolename: "超级管理员",
        menuname: "two",
      },
      {
        mid: 0,
        rolename: "超级管理员",
        menuname: "three",
      },
      {
        mid: 0,
        rolename: "管理员",
        menuname: "one",
      },
      {
        mid: 0,
        rolename: "管理员",
        menuname: "two",
      },
      {
        mid: 0,
        rolename: "普通用户",
        menuname: "one",
      },
    ];
    const newArr = [];
    arr.forEach((cur) => {
      const index = newArr.findIndex((newA) => newA.rolename === cur.rolename);
      index === -1
        ? newArr.push(cur)
        : (newArr[index].menuname = newArr[index].menuname.concat(
            "," + cur.menuname
          ));
    });
    console.log(newArr);

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