JSON Lib 转换数组对象

看到问答里面有人问这个问题。就是一个json字符串，转换成Java对象。json字符串如下：

[
{
"id": "1",
"fields": [
{"name": "age", "value": 10},
{"name": "id", "value": "1"},
{"name": "name", "value": "name-1"}
]
},
{
"id": "2",
"fields": [
{"name": "age", "value": 10},
{"name": "id", "value": "2"},
{"name": "name", "value": "name-2"}
]
}
] 

要求转换成：
List
Record
Field

上面json字符串是一个数组对象。因此不能使用net.sf.json.JSONObject.fromObject(jsonString)来转换，应该使用JSONArray.fromObject(jsonString)。JSONObject只转换单个对象。
在上面json字符串中对象里面还有一个集合类型。在这里就需要使用classMap来定义对应属性的集合元素类型。

Field：

public class Field {
	
	private String name;
	
	private String value;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getValue() {
		return value;
	}

	public void setValue(String value) {
		this.value = value;
	}
}

Record：

public class Record{
	
	private String id;
	
	private List<Field> fields;
	
	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public List<Field> getFields() {
		return fields;
	}

	public void setFields(List<Field> fields) {
		this.fields = fields;
	}
	
}

Test：

public class Test {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		
		String jsonString = "[{\"id\": \"1\",\"fields\": [{\"name\": \"age\", \"value\": 10},{\"name\": \"id\", \"value\": \"1\"},{\"name\": \"name\", \"value\": \"name-1\"}]},{\"id\": \"2\",\"fields\": [{\"name\": \"age\", \"value\": 10},{\"name\": \"id\", \"value\": \"2\"},{\"name\": \"name\", \"value\": \"name-2\"}]}]";

		JSONArray ja = JSONArray.fromObject(jsonString);

		Map<String, Class<Field>> classMap = new HashMap<String, Class<Field>>();
		classMap.put("fields", Field.class);

		List<Record> list = JSONArray.toList(ja, Record.class, classMap);

		for (Record record : list) {
			System.out.println("Record id:" + record.getId());

			for (Field field : record.getFields()) {
				System.out.println("Field name:" + field.getName());
				System.out.println("Field value:" + field.getValue());
			}
		}
	}

}

运行结果如下：

Record id:1
Field name:age
Field value:10
Field name:id
Field value:1
Field name:name
Field value:name-1
Record id:2
Field name:age
Field value:10
Field name:id
Field value:2
Field name:name
Field value:name-2