JSON取值前判断

public static void main(String[] args)throws Exception{
String jsonStr1="{\\"access_token\\":\\"OezXcEiiBSKSxW0eoylIeIVb08lFhyeFsq6cUJJNo8XYLoJjqYARJOZUrnqhfvnyMKOSjz5SHPHGUmt6f09_762MWQ0HLnZtffDPyD2A6TgCqWlZAEsHLhIaaQVYx1lywxOWQTrr7rX13i_w1INGnw\\",\\"expires_in\\":7200,\\"openid\\":\\"owYTUs68SXYX83wBvm_uN4Ya****\\",\\"scope\\":\\"snsapi_base\\"}";
String jsonStr2="{\\"access_token\\":\\"OezXcEiiBSKSxW0eoylIeIVb08lFhyeFsq6cUJJNo8XYLoJjqYARJOZUrnqhfvnyMKOSjz5SHPHGUmt6f09_762MWQ0HLnZtffDPyD2A6TgCqWlZAEsHLhIaaQVYx1lywxOWQTrr7rX13i_w1INGnw\\",\\"expires_in\\":7200,\\"refresh_token\\":\\"OezXcEiiBSKSxW0eoylIeIVb08lFhyeFsq6cUJJNo8XYLoJjqYARJOZUrnqhfvnyuq9ojibRxolf9ElS7PSM0Kz1OTNlJ8ZKJl2BfbPi0LA-nQ9uNVUE8ujLFsdCeP79_L9FmIYcmHLXWXnl-fUsVg\\",\\"openid\\":\\"owYTUs68SXYX83wBvm_uN4Y****\\",\\"scope\\":\\"snsapi_base\\"}";
JSONObject json1=JSONObject.fromObject(jsonStr1);
JSONObject json2=JSONObject.fromObject(jsonStr2);
String refresh_token_1=null;
String refresh_token_2=null;
if(json1.containsKey("refresh_token")){
refresh_token_1=json1.getString("refresh_token");
}
if(json2.containsKey("refresh_token")){
refresh_token_2=json2.getString("refresh_token");
}

System.out.println(refresh_token_1);
System.out.println(refresh_token_2);
}

运行结果: