尝试使用Gson库将Json解析为Java对象时抛出异常

Question

我试图创建一个Web方法谁会得到一个Json字符串。我需要获取该json字符串并将其解析为java对象。当我试图做到这一点时，我得到了例外：javax.servlet.ServletException: com.google.gson.JsonSyntaxException: java.io.EOFException: End of input at line 1 column 2根本原因com.google.gson.JsonSyntaxException: java.io.EOFException: End of input at line 1 column 2根本原因 java.io.EOFException: End of input at line 1 column 2那是我的代码：@GET@Produces("application/text")@Path("checkuser/{user}")public String checkUser(@PathParam("user") String mu) throws SQLException, ClassNotFoundException {    gson = new Gson();    modelUserGet = gson.fromJson(mu, ModelUser.class);    StringBuilder query = new StringBuilder();    query.append("SELECT user, password, email,");    query.append(" telephone, creation_data, last_update_data ");    query.append("FROM user ");    query.append("WHERE user ='");    query.append(modelUserGet.getUser());    query.append("' ");    datamysql = new DataMySqlAccess();    Statement st = datamysql.getConnection().createStatement();    ResultSet rs = st.executeQuery(query.toString());    String result = "";    if(rs.next() == true){        modelUserSend = new ModelUser(                rs.getString("user"),                rs.getString("password"),                rs.getString("email"),                rs.getString("telephone"),                rs.getString("creation_data"),                rs.getString("last_update_data")        );        if(!modelUserSend.getPassword().equals(modelUserGet.getPassword()))            result = "INVALID_PASSWORD";        else            result = "OK";    } else         result = "INVALID_USER";    modelUserSend.setCheckUserReponse(result);    return gson.toJson(modelUserSend);}

Answer 1

@PathParam（“ user”）字符串mu

这是您要获取的PathParameter，它是一个字符串。这就是例外的原因。它无法转换为模型。

在您的情况下，请将其作为单独的路径参数变量并在方法中使用它。

编辑1

我认为，用户名是您从参数中唯一需要的项目。因此，最好将用户名作为Path参数获取。其他细节，您正在从数据库中获取。

@GET

@Produces("application/text")

@Path("checkuser/{user}")

public String checkUser(@PathParam("user") String userName) throws SQLException, ClassNotFoundException {

StringBuilder query = new StringBuilder();

query.append("SELECT user, password, email,");

query.append(" telephone, creation_data, last_update_data ");

query.append("FROM user ");

query.append("WHERE user ='");

query.append(userName);

query.append("' ");

datamysql = new DataMySqlAccess();

Statement st = datamysql.getConnection().createStatement();

ResultSet rs = st.executeQuery(query.toString());

String result = "";

if(rs.next() == true){

    modelUserSend = new ModelUser(

            rs.getString("user"),

            rs.getString("password"),

            rs.getString("email"),

            rs.getString("telephone"),

            rs.getString("creation_data"),

            rs.getString("last_update_data")

    );

    if(!modelUserSend.getPassword().equals(modelUserGet.getPassword()))

        result = "INVALID_PASSWORD";

    else

        result = "OK";

} else 

    result = "INVALID_USER";

modelUserSend.setCheckUserReponse(result);

return gson.toJson(modelUserSend);

}