如何使用Java jsonGenerator制作json文件？

Question

I try to make this json format:

[{"x":1392440400000,"title":"!"},{"x":1392465600000,"title":"!"}]

I tried it out with the jsonGenerator

This is my code:

JsonFactory f = new JsonFactory();
StringWriter sw = new StringWriter();
JsonGenerator g = f.createJsonGenerator(sw);

    while {
     g.writeStartObject();
     g.writeNumberField("x",111111);
     g.writeStringField("title","!");
     g.writeEndObject();
    }

    g.close();
    return "["+sw.toString()+"]";   

But my output is like that ist like that: [{"x":1392440400000,"title":"!"} {"x":1392465600000,"title":"!"}]

Can anybody help me to make the correct Json output with a comma between the objects ?

Answer 1

I'm not using jackson, but for this specific scenario, you need your g.writeStartObject(); and g.writeEndObject(); inside the loop. (Because you're essentially trying to create an Array of Objects, right?)

Answer 2

You can use the ObjectMapper to generate the output. So this could be something like this.

ObjectMapper mapper = new ObjectMapper();
HashMap<String, Object> data = new HashMap<String, Object>();
data.put("x", 1392440400000l);
data.put("title", "!");

HashMap<String, Object> data2 = new HashMap<String, Object>();
data2.put("x", 1392440400000l);
data2.put("title", "!");

List out = new ArrayList();
out.add(data);
out.add(data2);

String val = mapper.writeValueAsString(out);