java foreach database List value

Question

data is selecte all users in database
it will print out:

[com.test.abc.user.domain.User@b22379c, com.test.abc.user.domain.User@364b96e5, com.test.abc.user.domain.User@1c9fb03c, com.test.abc.user.domain.User@37eb41d2]

I want to know how can I get the value in it .

I want to make it to json string like str so that the front end can get it
Please help me !!

@ResponseBody
public String getList() {

    List<User> data = memberObj.getCurrentMembers() ;
    System.out.println(data);

    //data to string

    String str = "{\"data\": [{\"id\": \"1\",\"account\": \"[email protected]\",\"name\": \"sky\",\"nick\": \"abc\"}]}";

    return str;
}

Arjit · Accepted Answer · 2015-05-26 09:35:30Z

1

Use google gson library

List<User> list = new ArrayList<User>();
list.add(new User());
list.add(new User());
String json = new Gson().toJson(list);

edited May 26, 2015 at 9:35

answered May 26, 2015 at 9:27

Arjit

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Comments

OldCurmudgeon · Accepted Answer · 2015-05-26 09:07:53Z

0

You need to give your User class a toString() method.

class User {

    String name;

    @Override
    public String toString() {
        return name;
    }
}

answered May 26, 2015 at 9:07

OldCurmudgeon

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2 Comments

npinti Over a year ago

I think that what the OP is after is some JSON encoding mechanism.

OldCurmudgeon Over a year ago

@npinti - It is difficult to tell isn't it.

mormod · Accepted Answer · 2015-05-26 09:10:17Z

0

When you printout data with

System.out.println(data)

you just print out the structure, not the objects in it.

Additionaly, you do the same here:

String str = "{\"data\": [{\"id\": \"1\",\"account\": \"[email protected]\",\"name\": \"sky\",\"nick\": \"abc\"}]}";

you just return an object not a value, you have to do this with a for or while loop.

answered May 26, 2015 at 9:10

mormod

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1 Comment

user2492364 Over a year ago

How to do the loop? I have no idea

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