string字符串转换成java对象或者对象数组

代码如下 

public class TestFastJson {
	public static void main(String[] args) {
		//  对象
		String jsonstring = "{\"a\":51,\"b\":0}";
		Usa usa = JSON.parseObject(jsonstring, new TypeReference<Usa>(){});
		// 对象数组 
		String jsonstring2 = "[{\"a\":51,\"b\":0}]";
		Usa[] usa2 = JSON.parseObject(jsonstring2, new TypeReference<Usa[]>(){});
	}
}
class Usa {
	private Long a;
	public Long getA() {
		return a;
	}
	public void setA(Long a) {
		this.a = a;
	}
	private String b;
	public String getB() {
		return b;
	}
	public void setB(String b) {
		this.b = b;
	}
}