在插入对象的SQLite数据库空例外

本文介绍了在插入对象的SQLite数据库空例外的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

林创建一个包含2的EditText领域一个非常基本的片段和一个提交按钮。在提交的值应该被插入一个一行到我的SQLite数据库。结果即时得到一个NullPointerException异常，我只是不明白..

在我的片段IM的onCreateView方法让我的字段值，并建立一个点击监听，是这样的：

查看rootView = inflater.inflate（R.layout.fragment_add_customer，集装箱，FALSE）;    客户名称=（EditText上）rootView.findViewById（R.id.editCompanyName）;    customerAddress =（EditText上）rootView.findViewById（R.id.editCompanyAddress）;    Add按钮=（按钮）rootView.findViewById（R.id.submitCustomerBtn）;    addButton.setOnClickListener（新View.OnClickListener（）{        @覆盖        公共无效的onClick（查看视图）{            字符串sCustomerName = customerName.getText（）的toString（）。            字符串sCustomerAddress = customerAddress.getText（）的toString（）。            如果（sCustomerName.trim（）长度（）方式＆gt; 0＆放大器;＆放大器; sCustomerAddress.trim（）长度（）方式＆gt; 0）{                客户客户=新客户（）;                customer.setName（sCustomerName）;                customer.setAddress（sCustomerAddress）;                customer.setLocation（未设置）;                customer.setImage（无）;                顾客= dataSource.createCustomer（客户）;                如果（customer.getId（）！= 0）{                    Toast.makeText（getActivity（），customer.getName（）+ID为：+ customer.getId（）+被创造！，Toast.LENGTH_LONG）.show（）;                    Log.i（LOGTAG，客户ID为创建+ customer.getId（））;                }            }其他{                Toast.makeText（getActivity（），请填写所有字段。Toast.LENGTH_LONG）.show（）;            }        }    }）;    返回rootView;

在我的DataSource类，其中i CONTROLE我的数据库查询和报表IM调用createCustomer方法，它看起来像这样：

公共客户createCustomer（客户的客户）{    ContentValues​​值=新ContentValues​​（）;    values​​.put（BusinessDBOpenHelper.CUSTOMER_NAME，customer.getName（））;    values​​.put（BusinessDBOpenHelper.CUSTOMER_ADDRESS，customer.getAddress（））;    values​​.put（BusinessDBOpenHelper.CUSTOMER_LOCATION，customer.getLocation（））;    values​​.put（BusinessDBOpenHelper.CUSTOMER_IMAGE，customer.getImage（））;    长insertid = database.insert（BusinessDBOpenHelper.TABLE_CUSTOMER，空，价值）;    customer.setId（insertid）;    回报客户;}

我的客户模型也只是containg长的ID，字符串名称，地址字符串，字符串位置，字符串图像的getter和setter ..结果空的例外是：

显示java.lang.NullPointerException：尝试调用虚拟方法org.example.app.model.Customer org.example.app.db.BusinessDataSource.createCustomer（org.example.app在一个空对象引用.model.Customer）        在org.example.app.AddCustomerFragment $ 1.onClick（Fragment.java:55）

解决方案

您

dataSource.createCustomer（客户）;

为空，你必须初始化

数据源

地方

Im creating a very basic fragment containing 2 EditText fields and a submit button. On submit the values should be inserted as a row to my SQLite DB. Im getting a NullPointerException i just dont get..

Inside my onCreateView method of the fragment im getting my field values and setting up a click listener like this:

View rootView = inflater.inflate(R.layout.fragment_add_customer, container, false); customerName = (EditText) rootView.findViewById(R.id.editCompanyName); customerAddress = (EditText) rootView.findViewById(R.id.editCompanyAddress); addButton = (Button) rootView.findViewById(R.id.submitCustomerBtn); addButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String sCustomerName = customerName.getText().toString(); String sCustomerAddress = customerAddress.getText().toString(); if(sCustomerName.trim().length() > 0 && sCustomerAddress.trim().length() > 0) { Customer customer = new Customer(); customer.setName(sCustomerName); customer.setAddress(sCustomerAddress); customer.setLocation("Not set"); customer.setImage("None"); customer = dataSource.createCustomer(customer); if(customer.getId() != 0) { Toast.makeText(getActivity(), customer.getName() + " with id: " + customer.getId() + " was created!", Toast.LENGTH_LONG).show(); Log.i(LOGTAG, "Customer created with id " + customer.getId()); } }else{ Toast.makeText(getActivity(), "Please fill all fields.", Toast.LENGTH_LONG).show(); } } }); return rootView;

Inside my dataSource class where i controle my DB query and statement im calling the createCustomer method, which looks like this:

public Customer createCustomer(Customer customer) { ContentValues values = new ContentValues(); values.put(BusinessDBOpenHelper.CUSTOMER_NAME, customer.getName()); values.put(BusinessDBOpenHelper.CUSTOMER_ADDRESS, customer.getAddress()); values.put(BusinessDBOpenHelper.CUSTOMER_LOCATION, customer.getLocation()); values.put(BusinessDBOpenHelper.CUSTOMER_IMAGE, customer.getImage()); long insertid = database.insert(BusinessDBOpenHelper.TABLE_CUSTOMER, null, values); customer.setId(insertid); return customer; }

My Customer model is also just containg long id, String name, String address, String location, String image with getters and setters.. The null exception is:

java.lang.NullPointerException: Attempt to invoke virtual method 'org.example.app.model.Customer org.example.app.db.BusinessDataSource.createCustomer(org.example.app.model.Customer)' on a null object reference at org.example.app.AddCustomerFragment$1.onClick(Fragment.java:55)

解决方案

Your

dataSource.createCustomer(customer);

is null, you have to initialize

dataSource

somewhere