张贴RESTFUL方法Java错误

Question

谁能告诉我为什么这个错误？

服务器日志：

 StandardWrapperValve[ws_site.ApplicationConfig]: Servlet.service() for servlet ws_site.ApplicationConfig threw exception
java.lang.IllegalStateException: Expected BEGIN_OBJECT but was STRING at line 1 column 5
at com.google.gson.stream.JsonReader.expect(JsonReader.java:339)
    at com.google.gson.stream.JsonReader.beginObject(JsonReader.java:322)
    at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:165)
    at com.google.gson.Gson.fromJson(Gson.java:791)

JavaScript函数，负责捕获填充表单的数据并发送到服务器：

function save()
{
    var str_name = $("#name").val();
    var str_email = $("#email").val();

    var str_country = $("#country").val();
    var str_state = $("#state").val();
    var str_city = $("#city").val();
    var str_zipcode = $("#zipcode").val();
    var str_neighborhood = $("#neighborhood").val();
    var str_street = $("#street").val();
    var str_number = $("#number").val();

    var objdata = '{"email_user":"' + str_email + '","name_user":"' + str_name}';
var objlocation = '{"country":"' + str_country + '","state":"' + str_state + '","city":"' + str_city + '","neighborhood":"' + str_neighborhood + '","street":"' + str_street + '","number":"' + str_number + '","zipcode":"' + str_zipcode + '"}';
    var obj = '{"user":['+objdata+'],"endereco":['+objlocation+']}';
    $.ajax({
        headers: {'content-type': 'application/json'},
        dataType: 'json',
        method: "POST",
        url: "http://localhost:8080/SystemExample/webservice/Save/data",
        data: obj
     }).done(function (data)
     {
        alert(data);
     });
}

RESTFUL JAVA方法：

@POST
@Path("data")
@Produces(MediaType.TEXT_PLAIN)
@Consumes({MediaType.APPLICATION_JSON})
public String registerUser(Gson json)  
{
    User u = json.fromJson("user", User.class);
    Address a = json.fromJson("endereco", Address.class);
    u.setAddress(a);
    userDAO.save(u);
    return "Saved successfully!";
}

保存USERDAO方法：

    public void save(User u) {
    EntityManager em = JPAUtil.getEntityManager();
    EntityTransaction tx = em.getTransaction();
    try {
        tx.begin();
        if (u.getId_User() == null) {
            em.persist(u);
        } else {
            em.merge(u);
        }
        tx.commit();
    } catch (Exception ex) {
        ex.printStackTrace();
        if (tx != null && tx.isActive()) {
            tx.rollback();
        }
    } finally {
        em.close();
    }
}

使用gson将JSON转换为对象

Answer 1

您没有向服务器发送对象，只是发送一个字符串：

var obj = '...';

而是发送一个对象：

var objdata = {
  "email_user": str_email,
  "name_user": str_name
};
var objlocation = {
  "country": str_country,
  "state": str_state,
  "city": str_city,
  "neighborhood": str_neighborhood,
  "street": str_street,
  "number": str_number,
  "zipcode": str_zipcode
};
var obj = {
  "user": [objdata],
  "endereco": [objlocation]
};

看起来像的字符串仍然是字符串。

Answer 2

objdata并未正确填充有效的JSON。尝试一下：

    function save() {
        var str_name = $("#name").val();
        var str_email = $("#email").val();
        var str_country = $("#country").val();
        var str_state = $("#state").val();
        var str_city = $("#city").val();
        var str_zipcode = $("#zipcode").val();
        var str_neighborhood = $("#neighborhood").val();
        var str_street = $("#street").val();
        var str_number = $("#number").val();
        var objdata = '{"email_user":"' + str_email + '","name_user":"' + str_name + '"}';
        console.log(objdata);
        var objlocation = '{"country":"' + str_country + '","state":"' + str_state + '","city":"' + str_city + '","neighborhood":"' + str_neighborhood + '","street":"' + str_street + '","number":"' + str_number + '","zipcode":"' + str_zipcode + '"}';
        console.log(objlocation);
        var obj = '{"user":[' + objdata + '],"endereco":[' + objlocation + ']}';
        console.log(obj);
        $.ajax({
            headers: {'content-type': 'application/json'},
            dataType: 'json',
            method: "POST",
            url: "http://localhost:8080/SystemExample/webservice/Save/data",
            data: JSON.parse(obj)
        }).done(function (data) {
            alert(data);
        });
    }

Answer 3

在您的服务器端您正在尝试绑定JSON数据。

User u = json.fromJson("user", User.class);
Address a = json.fromJson("endereco", Address.class);

这是指user和endereco应该是下面的JSON对象。

{
    "user":{
        "email_user":"str_mail","name_user":"nameeee"
    },
    "endereco":{
        "country":"str_country","state":"str_state","city":"str_city","neighborhood":"str_neighborhood","street":"str_street","number":"str_number","zipcode":"str_zipcode"
    }
}

但是，在您的情况下， user和 endereco实际上是jsonarray的（请参阅方括号。）。

{
    "user":[
        {
            "email_user":"str_mail",
            "name_user":"nameeee"
        }
    ],
    "endereco":[
        {
            "country":"str_country",
            "state":"str_state",
            "city":"str_city",
            "neighborhood":"str_neighborhood",
            "street":"str_street",
            "number":"str_number",
            "zipcode":"str_zipcode"
        }
    ]
}

所以在线下更改

var obj = '{"user":['+objdata+'],"endereco":['+objlocation+']}';

to

var obj = '{"user":'+objdata+',"endereco":'+objlocation+'}';