我有一个android文件，我从服务器中检索JSON数据，然后将其插入sqlite数据库，然后将其显示在listView customAdapter中。
但每次我去另一个活动并返回主要活动时，它会再次插入表中......我怎么能阻止这个？
这是代码：
package com.example.mvctest;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import sereen.sql.Details_info;
import sereen.sql.Info;
import sereen.sql.InfoServicesNew;
import android.os.AsyncTask;
import android.os.Bundle;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.util.Log;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
import android.widget.AdapterView.OnItemClickListener;
public class PenddingOrders extends Activity {
ArrayList<Info> info=new ArrayList<Info>();
ListView list;
ProgressDialog pd;
private String defValue = "N/A";
InfoServicesNew databaseHelper;
String name=InfoServicesNew.DB_TABLE_NAME;
String name2=InfoServicesNew.DB_TABLE_NAME5;
static int img=R.drawable.ex2;
String data;
Intent o;
int position;
Object object;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pendding_orders);
setTitle("الطلبات الجديدة");
databaseHelper = new InfoServicesNew(this);
list=(ListView)findViewById(R.id.listView1);
pd = new ProgressDialog(this);
new asy().execute("http://192.168.1.113/JsonRoot/transitions/Pendding_orders.json");
// new asy().execute("http://jsonblob.com/api/jsonBlob/53021f22e4b0f9ce1677329a");
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.pendding_orders, menu);
return true;
}
public class asy extends AsyncTask<String, String, ArrayList<Info>>
{
@Override
protected ArrayList<Info> doInBackground(String... params) {
// TODO Auto-generated method stub
//activity is defined as a global variable in your AsyncTask
try {
HttpClient hc = new DefaultHttpClient();
HttpGet hg = new HttpGet(params[0]);
HttpResponse hr = hc.execute(hg);
HttpEntity he = hr.getEntity();
data = EntityUtils.toString(he);
Log.i("data", data);
}
catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
ArrayList<Info> sereenlist = new ArrayList<Info>();
sereenlist = getJSONData(data);
return sereenlist;
}
private ArrayList<Info> getJSONData(String data) {
// TODO Auto-generated method stub
String id = null;
String item=null;
String amount=null;
String unit=null;
String price=null;
String total_price=null;
ArrayList<Info> rs = null;
try {
JSONObject obj = new JSONObject(data);
JSONArray finalObj = obj.optJSONArray("orders");
for (int i = 0; i < finalObj.length(); i++)
{
final String orderNumber = finalObj.optJSONObject(i).optString(
"order-number");
final String orderAmount = finalObj.optJSONObject(i).optString(
"order-amount");
final String date = finalObj.optJSONObject(i).optString(
"date");
final String client = finalObj.optJSONObject(i).optString(
"client");
final String upperLimit = finalObj.optJSONObject(i).optString(
"upper-limit");
final String debt = finalObj.optJSONObject(i).optString(
"debt");
JSONArray details = finalObj.getJSONObject(i).getJSONArray("details");
for(int j=0; j<details.length(); j++)
{
id = details.getJSONObject(j).optString("id");
item = details.getJSONObject(j).optString("item");
amount = details.getJSONObject(j).optString("amount");
unit = details.getJSONObject(j).optString("unit");
price = details.getJSONObject(j).optString("price");
total_price = details.getJSONObject(j).optString("total-price");
// Log.e("id", id);
// Log.e("item", item);
// Log.e("amount", amount);
// Log.e("unit", unit);
// Log.e("price", price);
// Log.e("total_price", total_price);
}
long id1=databaseHelper.insert(new Info(client,orderAmount,date ,orderNumber,upperLimit,debt,img),name);
databaseHelper.insert_details(new Details_info(id,item,amount ,unit,price,total_price,orderNumber),name2);
}
rs = databaseHelper.selectAll(name,img);
databaseHelper.close();
Log.i("size", finalObj.length()+"");
}//try end
catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return rs;
}
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
pd.setTitle("fetching");
pd.setMessage("waiting...");
pd.show();
}
@Override//
protected void onPostExecute(ArrayList<Info> result) {
// TODO Auto-generated method stub
ArrayList<Info> rs = null;
rs = databaseHelper.selectAll(name,img);
SetAdapterList(rs);
//SetAdapterList(result);
pd.dismiss();
}
private void SetAdapterList(ArrayList<Info> result)
{
// TODO Auto-generated method stub
CustomAdapter adapter=new CustomAdapter(getApplicationContext(), result);
list.setAdapter(adapter);
list.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
Intent i=new Intent(PenddingOrders.this,Details.class);
int myId=arg2;
object = list.getItemAtPosition(arg2);
Info detail = (Info) object;
String client = detail.getClient();
String orderAmount = detail.getOrderAmount();
String date=detail.getdate();
String orderNumber=detail.getorderNumber();
String upperLimit=detail.getupperLimit();
String debt=detail.getdept();
// Log.e("value is ", client);
// Log.e("value is1 ", orderAmount);
i.putExtra("myid", ""+myId);
i.putExtra("client", ""+ client);
i.putExtra("orderAmount", ""+orderAmount);
i.putExtra("date", date);
i.putExtra("orderNumber", orderNumber);
i.putExtra("upperLimit", upperLimit);
i.putExtra("debt", debt);
startActivity(i);
}
});
//
}
}
}
这是我的 InfoServiceNew.java 类：
package sereen.sql;
import java.util.ArrayList;
import java.util.List;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
public class InfoServicesNew extends SQLiteOpenHelper{
private String KEY_ID = "ID";
private String KEY_CLIENT = "CLIENT";
private String KEY_ORDER_AMOUNT = "ORDERAMOUNT";
private String KEY_DATE = "DATE";
private String KEY_ORDER_NUMBER = "ORDERNUMBER";
private String KEY_UPPER_LIMIT = "UPPERLIMIT";
private String KEY_DEBT = "DEBT";
private String KEY_ITEM_ID = "ITEMID";
private String KEY_ITEM = "ITEM";
private String KEY_AMOUNT = "AMOUNT";
private String KEY_UNIT = "UNIT";
private String KEY_PRICE = "PRICE";
private String KEY_TOTAL_PRICE = "TOTALPRICE";
private static String DB_NAME = "FUCHES";
public static String DB_TABLE_NAME = "PENDDINGORDERS";
public static String DB_TABLE_NAME2 = "APPROVEDORDERS";
public static String DB_TABLE_NAME3 = "DENIEDORDERS";
public static String DB_TABLE_NAME4 = "HISTORY";
public static String DB_TABLE_NAME5 = "DETAILS";
private static int DB_VERSION = 16;
private static SQLiteDatabase database;
public InfoServicesNew(Context context) {
super(context, DB_NAME, null, DB_VERSION);
database = getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + DB_TABLE_NAME + " (" + KEY_ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT , " + KEY_CLIENT+" TEXT," +
KEY_ORDER_AMOUNT+" TEXT," +
KEY_DATE +" TEXT," + KEY_ORDER_NUMBER + " TEXT ," +
KEY_UPPER_LIMIT + " TEXT ,"+ KEY_DEBT +" TEXT );");
db.execSQL("CREATE TABLE " + DB_TABLE_NAME2 + " (" + KEY_ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT , " + KEY_CLIENT+" TEXT," +
KEY_ORDER_AMOUNT+" TEXT," +
KEY_DATE +" TEXT," + KEY_ORDER_NUMBER + " TEXT ," +
KEY_UPPER_LIMIT + " TEXT ,"+ KEY_DEBT +" TEXT );");
db.execSQL("CREATE TABLE " + DB_TABLE_NAME3 + " (" + KEY_ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT , " + KEY_CLIENT+" TEXT," +
KEY_ORDER_AMOUNT+" TEXT," +
KEY_DATE +" TEXT," + KEY_ORDER_NUMBER + " TEXT ," +
KEY_UPPER_LIMIT + " TEXT ,"+ KEY_DEBT +" TEXT );");
db.execSQL("CREATE TABLE " + DB_TABLE_NAME4 + " (" + KEY_ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT , " + KEY_CLIENT+" TEXT," +
KEY_ORDER_AMOUNT+" TEXT," +
KEY_DATE +" TEXT," + KEY_ORDER_NUMBER + " TEXT ," +
KEY_UPPER_LIMIT + " TEXT ,"+ KEY_DEBT +" TEXT );");
db.execSQL("CREATE TABLE " + DB_TABLE_NAME5 + " (" + KEY_ID
+ " INTEGER PRIMARY KEY AUTOINCREMENT , " + KEY_ITEM_ID+" TEXT," + KEY_ORDER_NUMBER+" TEXT," +
KEY_ITEM+" TEXT," +
KEY_AMOUNT +" TEXT," + KEY_UNIT + " TEXT ," +
KEY_PRICE + " TEXT ,"+ KEY_TOTAL_PRICE +" TEXT );");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE_NAME);
db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE_NAME2);
db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE_NAME3);
db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE_NAME4);
db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE_NAME5);
onCreate(db);
}
public ArrayList<Info> selectAll(String Db_name, int img) {
String columns[] = new String[] { KEY_ID, KEY_CLIENT,KEY_ORDER_AMOUNT, KEY_DATE ,KEY_ORDER_NUMBER,KEY_UPPER_LIMIT,KEY_DEBT};
Cursor c = database.query(Db_name, columns, null, null,null,null,null);
int idIndex = c.getColumnIndex(KEY_ID);
int clientIndex = c.getColumnIndex(KEY_CLIENT);
int orderamountIndex = c.getColumnIndex(KEY_ORDER_AMOUNT);
int dateIndex = c.getColumnIndex(KEY_DATE);
int ordernumberIndex = c.getColumnIndex(KEY_ORDER_NUMBER);
int upperlimitIndex = c.getColumnIndex(KEY_UPPER_LIMIT);
int deptIndex = c.getColumnIndex(KEY_DEBT);
ArrayList<Info> list = new ArrayList<Info>();
if (c.moveToFirst()) {
do {
list.add(new Info(c.getInt(idIndex), c.getString(clientIndex), c.getString(orderamountIndex), c.getString(dateIndex),c.getString(ordernumberIndex),c.getString(upperlimitIndex),c.getString(deptIndex),img));
} while (c.moveToNext());
}
return list;
}
public ArrayList<Details_info> selectAllDetails(String Db_name) {
String columns[] = new String[] { KEY_ID, KEY_ITEM_ID,KEY_ORDER_NUMBER,KEY_ITEM, KEY_AMOUNT ,KEY_UNIT,KEY_PRICE,KEY_TOTAL_PRICE};
Cursor c = database.query(Db_name, columns, null, null,null,null,null);
int idIndex = c.getColumnIndex(KEY_ID);
int itemidIndex = c.getColumnIndex(KEY_ITEM_ID);
int ordernumberIndex = c.getColumnIndex(KEY_ORDER_NUMBER);
int itemIndex = c.getColumnIndex(KEY_ITEM);
int amountIndex = c.getColumnIndex(KEY_AMOUNT);
int unitIndex = c.getColumnIndex(KEY_UNIT);
int priceIndex = c.getColumnIndex(KEY_PRICE);
int totalpriceIndex = c.getColumnIndex(KEY_TOTAL_PRICE);
ArrayList<Details_info> list = new ArrayList<Details_info>();
if (c.moveToFirst()) {
do {
list.add(new Details_info(c.getInt(idIndex), c.getString(itemidIndex), c.getString(ordernumberIndex), c.getString(itemIndex),c.getString(amountIndex),c.getString(unitIndex),c.getString(priceIndex),c.getString(totalpriceIndex)));
} while (c.moveToNext());
}
return list;
}
public long insert(Info info, String DB_name) {
ContentValues cv = new ContentValues();
cv.put(KEY_CLIENT, info.getClient());
cv.put(KEY_ORDER_AMOUNT, info.getOrderAmount());
cv.put(KEY_DATE, info.getdate());
cv.put(KEY_ORDER_NUMBER, info.getorderNumber());
cv.put(KEY_UPPER_LIMIT, info.getupperLimit());
cv.put(KEY_DEBT, info.getdept());
return database.insert(DB_name, null, cv);
}
public long update(Info info,String DB_name) {
ContentValues cv = new ContentValues();
cv.put(KEY_CLIENT, info.getClient());
cv.put(KEY_ORDER_AMOUNT, info.getOrderAmount());
cv.put(KEY_DATE, info.getdate());
cv.put(KEY_ORDER_NUMBER, info.getorderNumber());
cv.put(KEY_UPPER_LIMIT, info.getupperLimit());
cv.put(KEY_DEBT, info.getdept());
return database.update(DB_name, cv,
KEY_ID + " = " + info.getId(), null);
}
public long insert_details(Details_info detail, String name2) {
// TODO Auto-generated method stub
ContentValues cv = new ContentValues();
cv.put(KEY_ITEM_ID, detail.getItemid());
cv.put(KEY_ITEM , detail.getItem());
cv.put(KEY_AMOUNT, detail.getAmount());
cv.put(KEY_UNIT, detail.getUnit());
cv.put(KEY_PRICE, detail.getPrice());
cv.put(KEY_TOTAL_PRICE, detail.getTotalprice());
cv.put(KEY_ORDER_NUMBER, detail.getOrdernumber());
return database.insert(name2, null, cv);
}
public long update_details(Details_info detail,String DB_name) {
ContentValues cv = new ContentValues();
cv.put(KEY_ITEM_ID, detail.getItemid());
cv.put(KEY_ITEM , detail.getItem());
cv.put(KEY_AMOUNT, detail.getAmount());
cv.put(KEY_UNIT, detail.getUnit());
cv.put(KEY_PRICE, detail.getPrice());
cv.put(KEY_TOTAL_PRICE, detail.getTotalprice());
cv.put(KEY_ORDER_NUMBER, detail.getOrdernumber());
return database.update(DB_name, cv,
KEY_ID + " = " + detail.getId(), null);
}
public long delete_details(int id,String Db_name) {
return database.delete(Db_name, KEY_ID + " = " + id, null);
}
public long delete(int id, String name2) {
// TODO Auto-generated method stub
return database.delete(name2, KEY_ID + " = " + id, null) ;
}
}
答案 0 :(得分：2)
您可以使用SharedPreference来监控插入状态。创建一个boolean SharedPreference，其默认值为false，当您插入值时，请将其值设为true并在每次输入此代码时检查此首选项。对代码使用以下两种方法
第一次将日期插入数据库后，请调用以下方法。
Setter：
public void setInsertedToDB(){
SharedPreferences sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);
Editor editor = sharedpreferences.edit();
editor.putBoolean("key", true);
editor.commit();
}
在添加到数据库之前检查以下方法return。
<强>吸气剂：
public boolean isInsertedBeforeToDB(){
SharedPreferences sharedpreferences = getSharedPreferences(MyPREFERENCES, Context.MODE_PRIVATE);
sharedpreferences.getBoolean("key", false);//False is the default value
}
有关SharedPreferences的详情，请阅读此link。我希望它有所帮助。
使用SQLite：
您可以使用Row功能为所需的OnConflect IGNORE创建唯一属性。
示例：
id INTEGER PRIMARY_KEY ON CONFLICT REPLACE
答案 1 :(得分：1)
由于您希望按会话插入一次数据，您可以按以下方式执行检查操作，
if ( isDataLoaded ) // a boolean variable for checking
{
rs = databaseHelper.selectAll(name,img);
SetAdapterList(rs);
}
else
{
// new asy().execute("http://192.168.1.113/JsonRoot/transitions/Pendding_orders.json");
new asy().execute("http://jsonblob.com/api/jsonBlob/53021f22e4b0f9ce1677329a");
}
以下是完整的工作代码：
public class PenddingOrders extends Activity {
ArrayList<Info> info=new ArrayList<Info>();
static boolean isDataLoaded = false;
ListView list;
ProgressDialog pd;
private String defValue = "N/A";
InfoServicesNew databaseHelper;
String name=InfoServicesNew.DB_TABLE_NAME;
String name2=InfoServicesNew.DB_TABLE_NAME5;
static int img=R.drawable.ex2;
String data;
Intent o;
int position;
Object object;
ArrayList<Info> rs = null;
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pendding_orders);
setTitle("الطلبات الجديدة");
if ( databaseHelper == null )
{
databaseHelper = new InfoServicesNew(this);
}
System.out.println ( "isDataLoaded:" + isDataLoaded );
list = (ListView)findViewById(R.id.listView1);
pd = new ProgressDialog(this);
if ( isDataLoaded )
{
rs = databaseHelper.selectAll(name,img);
SetAdapterList(rs);
}
else
{
// new asy().execute("http://192.168.1.113/JsonRoot/transitions/Pendding_orders.json");
new asy().execute("http://jsonblob.com/api/jsonBlob/53021f22e4b0f9ce1677329a");
}
}
private void SetAdapterList(ArrayList<Info> result)
{
// TODO Auto-generated method stub
CustomAdapter adapter=new CustomAdapter(getApplicationContext(), result);
list.setAdapter(adapter);
System.out.println ( "Size : " + list.getCount() );
list.setOnItemClickListener(new OnItemClickListener()
{
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3)
{
// TODO Auto-generated method stub
Intent i=new Intent(PenddingOrders.this,Details.class);
int myId=arg2;
object = list.getItemAtPosition(arg2);
Info detail = (Info) object;
String client = detail.getClient();
String orderAmount = detail.getOrderAmount();
String date=detail.getdate();
String orderNumber=detail.getorderNumber();
String upperLimit=detail.getupperLimit();
String debt=detail.getdept();
i.putExtra("myid", ""+myId);
i.putExtra("client", ""+ client);
i.putExtra("orderAmount", ""+orderAmount);
i.putExtra("date", date);
i.putExtra("orderNumber", orderNumber);
i.putExtra("upperLimit", upperLimit);
i.putExtra("debt", debt);
startActivity(i);
finish();
}
});
//
}
public class asy extends AsyncTask<String, String, ArrayList<Info>>
{
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
pd.setTitle("fetching");
pd.setMessage("waiting...");
pd.show();
}
@Override
protected ArrayList<Info> doInBackground(String... params) {
// TODO Auto-generated method stub
//activity is defined as a global variable in your AsyncTask
try {
HttpClient hc = new DefaultHttpClient();
HttpGet hg = new HttpGet(params[0]);
HttpResponse hr = hc.execute(hg);
HttpEntity he = hr.getEntity();
data = EntityUtils.toString(he);
Log.i("data", data);
}
catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
ArrayList<Info> sereenlist = new ArrayList<Info>();
sereenlist = getJSONData(data);
return sereenlist;
}
private ArrayList<Info> getJSONData(String data) {
// TODO Auto-generated method stub
String id = null;
String item=null;
String amount=null;
String unit=null;
String price=null;
String total_price=null;
ArrayList<Info> rs = null;
if ( isDataLoaded == false )
{
try
{
JSONObject obj = new JSONObject(data);
JSONArray finalObj = obj.optJSONArray("orders");
for (int i = 0; i < finalObj.length(); i++)
{
final String orderNumber = finalObj.optJSONObject(i).optString(
"order-number");
final String orderAmount = finalObj.optJSONObject(i).optString(
"order-amount");
final String date = finalObj.optJSONObject(i).optString(
"date");
final String client = finalObj.optJSONObject(i).optString(
"client");
final String upperLimit = finalObj.optJSONObject(i).optString(
"upper-limit");
final String debt = finalObj.optJSONObject(i).optString(
"debt");
JSONArray details = finalObj.getJSONObject(i).getJSONArray("details");
for(int j=0; j<details.length(); j++)
{
id = details.getJSONObject(j).optString("id");
item = details.getJSONObject(j).optString("item");
amount = details.getJSONObject(j).optString("amount");
unit = details.getJSONObject(j).optString("unit");
price = details.getJSONObject(j).optString("price");
total_price = details.getJSONObject(j).optString("total-price");
}
long id1=databaseHelper.insert(new Info(client,orderAmount,date,orderNumber,upperLimit,debt,img),name);
databaseHelper.insert_details(new Details_info(id,item,amount,unit,price,total_price,orderNumber),name2);
}
rs = databaseHelper.selectAll(name,img);
Log.i("size", finalObj.length()+"");
}//try end
catch (JSONException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
return rs;
}
@Override//
protected void onPostExecute(ArrayList<Info> result)
{
// TODO Auto-generated method stub
//SetAdapterList(result);
isDataLoaded = true;
rs = databaseHelper.selectAll(name,img);
SetAdapterList(rs);
pd.dismiss();
}
}
@Override
public void onStop()
{
super.onStop();
if ( databaseHelper != null )
{
databaseHelper.close();
}
System.out.println ( "db closed" );
}
}