在java里拼接JSON

1. 错误的格式：

{"success":"0", "typesWithSelectControlJson":[], "parentTypesJson":"", "id":"51678"}

"parentTypesJson":""：这里的“”有问题，因为这里需要传递数组，所以是“”这个有问题。

2. 错误的格式：

{"success":"0", "typesWithSelectControlJson":[], "parentTypesJson":, "id":51669}

"parentTypesJson": 这里冒号后面就为空了，拼接还是有问题。

3. 正确的格式：{"success":"0", "typesWithSelectControlJson":[], "parentTypesJson":[], "id":"51686"}

String typesWithSelectControlJson = "[]";

String parentTypesJson = "[]";

String result = "{\"success\":\"0\", \"typesWithSelectControlJson\":" + typesWithSelectControlJson + ", \"parentTypesJson\":" + parentTypesJson + ", \"id\":\"" + id + "\"}";

如果是数组，当这个拼接的数据为空时一定要写[].

因为这个问题，同事帮我调式了好久。哎，最后我发现是这个问题，好坑爹。

最后需要的效果：

<span style="font-size:14px;">[{"success":"0", "typesWithSelectControlJson":[{"id":3,"typeName":"OS","parentId":2,"controlStyle":2,"deleteFlag":0,"parentName":"Design","typeValues":[],"childTypes":[],"typeNameStr":""},{"id":4,"typeName":"Demensions","parentId":2,"controlStyle":2,"deleteFlag":0,"parentName":"Design","typeValues":[],"childTypes":[],"typeNameStr":""},{"id":51666,"typeName":"2","parentId":2,"controlStyle":2,"deleteFlag":0,"parentName":"Design","typeValues":[],"childTypes":[],"typeNameStr":""},{"id":51667,"typeName":"a","parentId":2,"controlStyle":2,"deleteFlag":0,"parentName":"Design","typeValues":[],"childTypes":[],"typeNameStr":""},{"id":51668,"typeName":"3","parentId":0,"controlStyle":2,"deleteFlag":0,"parentName":"-","typeValues":[],"childTypes":[],"typeNameStr":""}], "parentTypesJson":[{"id":2,"typeName":"Design","parentId":0,"controlStyle":1,"deleteFlag":0,"parentName":null,"typeValues":[],"childTypes":[],"typeNameStr":""},{"id":6,"typeName":"Hardware","parentId":0,"controlStyle":1,"deleteFlag":0,"parentName":null,"typeValues":[],"childTypes":[],"typeNameStr":""},{"id":51665,"typeName":"1","parentId":0,"controlStyle":0,"deleteFlag":0,"parentName":"-","typeValues":[],"childTypes":[],"typeNameStr":""},{"id":51668,"typeName":"3","parentId":0,"controlStyle":2,"deleteFlag":0,"parentName":"-","typeValues":[],"childTypes":[],"typeNameStr":""}], "id":"51668"}]</span>