大家好，我有一个奇怪的团队。我正在尝试在应用程序中调试 SQLite DB。如果我执行查询SELECT * from table，我会得到 33 个结果，但如果我迭代游标，它会以结果 #17 结束。
这是我的调试类(有问题的方法是 public static void WriteToFile(Cursorcursor, String query , String table, String uri)):
package com.s2u.android.ps;
import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.List;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Environment;
import android.util.Log;
import com.s2u.android.ps.BO.App;
import com.s2u.android.ps.BO.AppMember;
import com.s2u.android.ps.datamodel.DatabaseManager;
import com.s2u.android.ps.networkApis.AndroidLog;
import com.s2u.android.ps.networkApis.AppConfig;
public class DebugToFile {
private static String TAG = "DebugToFile";
private static File path = new File(Environment.getExternalStorageDirectory() + "/ps_debug");
public static void WriteToFile(String lines , String tag)
{
WriteToFile(lines , tag , "txt");
}
public static void WriteToFile(String lines , String tag , String ext)
{
if (!Validate("WriteToFile(String lines)"))
return;
File file = new File(path, tag + "_" + GetDateStampTens() + "." + ext);
try
{
FileWriter fw = new FileWriter(file.getAbsolutePath() , true);
PrintWriter pw = new PrintWriter(fw);
pw.println(GetDateStamp() + " - " + lines);
pw.println();
pw.flush();
pw.close();
//Log.e(TAG, "WriteToFile(String lines) - " + file.toString());
}
catch (Exception e)
{
Log.e(TAG, "WriteToFile(String lines) failed!", e);
}
}
public static void WriteToFileAppMember(ArrayList<AppMember> appMembers , String tag)
{
if (!Validate("WriteToFile(AppMember)"))
return;
File file = new File(path, tag + "_" + GetDateStampTens() + ".csv");
try
{
FileWriter fw = new FileWriter(file.getAbsolutePath() , true);
PrintWriter pw = new PrintWriter(fw);
pw.println(GetDateStamp() + " - " + "AppMembers");
boolean doOnce = true;
for(com.s2u.android.ps.BO.AppMember appMember : appMembers)
{
if (doOnce)
{
doOnce = false;
pw.println(appMember.getCsvLabels());
}
pw.println(appMember.getCsvString());
}
pw.println();
pw.flush();
pw.close();
//Log.e(TAG, "WriteToFile(String lines) - " + file.toString());
}
catch (Exception e)
{
Log.e(TAG, "WriteToFile(String lines) failed!", e);
}
}
public static void WriteToFileAppMember(List<AppMember> appMembers , String tag)
{
if (!Validate("WriteToFile(AppMember)"))
return;
File file = new File(path, tag + "_" + GetDateStampTens() + ".csv");
try
{
FileWriter fw = new FileWriter(file.getAbsolutePath() , true);
PrintWriter pw = new PrintWriter(fw);
pw.println(GetDateStamp() + " - " + "AppMembers");
boolean doOnce = true;
for(com.s2u.android.ps.BO.AppMember appMember : appMembers)
{
if (doOnce)
{
doOnce = false;
pw.println(appMember.getCsvLabels());
}
pw.println(appMember.getCsvString());
}
pw.println();
pw.flush();
pw.close();
//Log.e(TAG, "WriteToFile(String lines) - " + file.toString());
}
catch (Exception e)
{
Log.e(TAG, "WriteToFile(String lines) failed!", e);
}
}
public static void WriteToFileApps(List<App> apps , String tag)
{
if (!Validate("WriteToFile(AppMember)"))
return;
File file = new File(path, tag + "_" + GetDateStampTens() + ".csv");
try
{
FileWriter fw = new FileWriter(file.getAbsolutePath() , true);
PrintWriter pw = new PrintWriter(fw);
pw.println(GetDateStamp() + " - " + "App objects");
boolean doOnce = true;
for(com.s2u.android.ps.BO.App app : apps)
{
if (doOnce)
{
doOnce = false;
pw.println(app.getCsvLabels());
}
pw.println(app.getCsvString());
}
pw.println();
pw.flush();
pw.close();
//Log.e(TAG, "WriteToFile(String lines) - " + file.toString());
}
catch (Exception e)
{
Log.e(TAG, "WriteToFile(String lines) failed!", e);
}
}
public static void WriteToFile(Cursor cursor, String query , String tables, String uri)
{
if (!Validate("WriteToFile(cursor)"))
return;
File file = new File(path, uri + "_" + GetDateStampTens() + ".csv");
try
{
FileWriter fw = new FileWriter(file.getAbsolutePath(), true);
PrintWriter pw = new PrintWriter(fw);
int resultCount = cursor.getCount();
pw.println("time: " + GetDateStamp());
pw.println("tables: " + tables);
pw.println("query: " + query);
pw.println("result count: " + Integer.toString(resultCount));
int row = 0;
String labels = "row,";
int startPosition = cursor.getPosition();
cursor.moveToPosition(-1);
while (cursor.moveToNext())
{
int colCount = cursor.getColumnCount();
row++;
if (row >= resultCount)
{
pw.println("Error! rows >= cursor count -- at row : " + Integer.toString(row) );
break;
}
StringBuilder line = new StringBuilder(512);
if (colCount <= 0)
pw.println("Empty row?");
for(int i = 0; i < colCount; i++)
{
if (row == 1)
{
labels += cursor.getColumnName(i) + "[" + GetCursorFieldTypeString(cursor, i) + "]";
if (i < colCount - 1)
labels += ",";
}
if (i == 0)
line.append(Integer.toString(row) + ",");
line.append(GetCursorString(cursor, i));
if (i < colCount - 1)
{
line.append(",");
}
}
if (row == 1)
pw.println(labels);
pw.println(line.toString());
cursor.moveToNext();
if (row > 100)
{
pw.println("max rows output - stopped at row: " + Integer.toString(row));
break;
}
}
pw.println("END");
pw.println();
pw.flush();
pw.close();
//Log.e(TAG, "WriteToFile(cursor) - " + file.toString());
cursor.moveToPosition(startPosition);
}
catch (Exception e)
{
Log.e(TAG, "WriteToFile(cursor) failed!", e);
}
}
private static boolean Validate(String methodName)
{
if (!AppConfig.isTestBuild())
{
Log.i(TAG, methodName + " - this is not a test build!");
return false;
}
if (!isExternalStorageWritable())
{
AndroidLog.e(TAG, methodName + " - external storage not accessible");
return false;
}
if (!path.exists())
{
path.mkdir();
if (!path.exists())
{
AndroidLog.e(TAG, methodName + " - directory doesn't exist and couldn't create it: " + path.toString());
return false;
}
}
return true;
}
private static String GetDateStamp()
{
Calendar c = Calendar.getInstance();
SimpleDateFormat df = new SimpleDateFormat("yyyyMMdd-kk:mm:ss.SSS");
String date = df.format(c.getTime());
return date;
}
private static String GetDateStampTens()
{
String date = GetDateStamp();
date = date.substring(0,date.length() - 1) + "0";
return date;
}
private static boolean isExternalStorageWritable() {
String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
return true;
}
return false;
}
private static String GetCursorString(Cursor cursor, Integer i)
{
String result = "undefined";
switch(cursor.getType(i))
{
case Cursor.FIELD_TYPE_NULL:
result = "NULL";
break;
case Cursor.FIELD_TYPE_BLOB:
result = "BLOB length: " + Integer.toString(cursor.getBlob(i).length);
break;
case Cursor.FIELD_TYPE_FLOAT:
result = Float.toString(cursor.getFloat(i));
break;
case Cursor.FIELD_TYPE_INTEGER:
result = Integer.toString(cursor.getInt(i));
break;
case Cursor.FIELD_TYPE_STRING:
result = cursor.getString(i);
break;
default:
result = "undefined cursor value type(" + Integer.toString(cursor.getType(i)) + ") -- try getString: " + cursor.getString(i);
}
result.replace("", " ");
return result;
}
private static String GetCursorFieldTypeString(Cursor cursor, Integer i)
{
String result = "UNK";
switch(cursor.getType(i))
{
case Cursor.FIELD_TYPE_NULL:
result = "NULL";
break;
case Cursor.FIELD_TYPE_BLOB:
result = "BLOB";
break;
case Cursor.FIELD_TYPE_FLOAT:
result = "F";
break;
case Cursor.FIELD_TYPE_INTEGER:
result = "INT";
break;
case Cursor.FIELD_TYPE_STRING:
result = "STR";
break;
default:
result = "UNK(" + Integer.toString(cursor.getType(i)) + ") ";
}
return result;
}
public static String AppListTypeToString(int appListType)
{
if (appListType == 0)
return "kAppListMain";
else if (appListType == 1)
return "kAppListProfile";
else if (appListType == 2)
return "kAppListPromoted";
return "unknown list type int: " + Integer.toString(appListType);
}
public static void DumpDatabaseToFiles(DatabaseManager db)
{
SQLiteDatabase readableDb = db.getReadableDatabase();
DumpDatabaseToFiles(readableDb);
}
public static void DumpDatabaseToFiles(SQLiteDatabase db)
{
if (!Validate("DumpDatabaseToFiles"))
return;
Cursor c = db.rawQuery("SELECT name FROM sqlite_master WHERE type='table'", null);
if (c.getCount() <= 0)
{
WriteToFile("table name count: " + Integer.toString(c.getCount()) , "dbdump_err");
c.close();
return;
}
//AndroidLog.i(TAG , "DumpDB table count: " + Integer.toString(c.getCount()));
List<String> tableNames = new ArrayList<String>();
if (c.moveToFirst())
{
while(!c.isAfterLast())
{
tableNames.add(c.getString(c.getColumnIndex("name")));
c.moveToNext();
}
}
c.close();
for (int i = 0; i < tableNames.size(); i++)
{
String table = tableNames.get(i);
c = db.rawQuery("SELECT * FROM " + table + " LIMIT 100 ", null);
WriteToFile(c, "all" , table, table);
c.close();
}
}
}
输出的 csv 文件是:
tables: app - from AppDAO.bulkInsertApp
query: SELECT * FROM app
result count: 33
row,_id[INT],packageName[STR],appName[STR],iconUrl1[STR],iconUrl2[NULL],publisher[STR],publisherEmail[NULL],price[INT],currency[STR],version[STR],category[STR],releaseDate[NULL],updatedOn[NULL],hasTried[INT],promo_url[NULL],promoParam[NULL],promoValueKey[NULL]
1,8192,com.shared2you.android.powerslyde,Powerslyde,https://lh5.ggpht.com/1qigt9Zz7oh5kTFiIS9ukJljVTm7W-Ur34XzcaQhFjc9GlMzATJ-ATRwYB6gxQhscHEU=w300,NULL,Shared2you, Inc.,NULL,0,, 1.08 ,Lifestyle,NULL,NULL,1,NULL,NULL,NULL
2,8219,com.android.providers.downloads.ui,com.android.providers.downloads.ui,NULL,NULL,NULL,NULL,NULL,,NULL,NULL,NULL,NULL,1,NULL,NULL,NULL
3,8225,com.google.android.apps.maps,Maps,https://lh3.ggpht.com/JW-F0fkeBHpKyh8lDcyQ7CveTRynYGByVBH9hUqnJxw4x64ORhoFJISdOWhekULemw0=w300,NULL,Google Inc.,NULL,0,, Varies with devic,Travel & Local,NULL,NULL,1,NULL,NULL,NULL
4,8231,com.android.vending,com.android.vending,NULL,NULL,NULL,NULL,NULL,,NULL,NULL,NULL,NULL,1,NULL,NULL,NULL
5,8246,com.google.android.apps.magazines,Google Play Newsstand,https://lh5.ggpht.com/rowOPaiODov-bNG7rnD6awPZwLnOc7Vzab-29GpfvB6jfE8DhOR42owBqAmLUXj-W2sI=w300,NULL,Google Inc.,NULL,0,, 3.1.0 ,News & Magazines,NULL,NULL,1,NULL,NULL,NULL
6,8248,com.google.android.gm,Gmail,https://lh4.ggpht.com/Ebn-CW55BnkwG7ng5nuGpijVpJeabTa-uPijd4keKbHpedz29SvDj3EZkfr20ZZzznE=w300,NULL,Google Inc.,NULL,0,, Varies with devic,Communication,NULL,NULL,1,NULL,NULL,NULL
7,8250,com.google.android.music,Google Play Music,https://lh6.ggpht.com/5opWBg-m6yFcjWzJz1LlT05YIf2Alyiy9YtpQm1f6U42LXWmCvB54M1zEkV9-hCaoTc=w300,NULL,Google Inc.,NULL,0,, Varies with devic,Music & Audio,NULL,NULL,1,NULL,NULL,NULL
8,8253,com.google.android.videos,Google Play Movies & TV,https://lh5.ggpht.com/fFPQTALNNU4xflvbazvbwPL5o4X3a_CqYHUWIh4FXmfU78aSSuP1OMkGXhXouxXzWPov=w300,NULL,Google Inc.,NULL,0,, Varies with devic,Media & Video,NULL,NULL,1,NULL,NULL,NULL
9,8312,com.android.chrome,Chrome Browser - Google,https://lh6.ggpht.com/lum4KYB0TtgvR-8vRMUZ_JhRnMQ4YqBIR0yjspc4ETsM9iJ8-4YHZ0s0HO9i0ez_=w300,NULL,Google Inc.,NULL,0,, Varies with devic,Communication,NULL,NULL,1,NULL,NULL,NULL
10,8316,com.google.android.calendar,Google Calendar,https://lh5.ggpht.com/qgUPYBPSTb61cPrijI9YXV3BEy00t5bhoBugDpEXTdEsQEv9B9-j8_ZDs_ClQzPbskc=w300,NULL,Google Inc.,NULL,0,, 201308023 ,Productivity,NULL,NULL,1,NULL,NULL,NULL
11,8433,com.estrongs.android.pop,ES File Explorer File Manager,https://lh5.ggpht.com/P31CiAbF5UMC1wbJxv2sPT4tSLLqfqUZPp8N0ATEaA0ZeMxXv_NjVDiswVKjeUUSS2w=w300,NULL,ES APP Group,NULL,0,, Varies with devic,Productivity,NULL,NULL,1,NULL,NULL,NULL
12,8867,com.devhd.feedly,Feedly,https://lh4.ggpht.com/rkouDgWbT3WNztDRa5QvnN8SatDK3zeHHwOMHZbiu2Vlf3-9hLlmH89W9gJpGEtxo3U=w300,NULL,Feedly Team,NULL,0,, 18.1.2 ,News & Magazines,NULL,NULL,1,NULL,NULL,NULL
13,8917,com.google.android.email,com.google.android.email,NULL,NULL,NULL,NULL,NULL,,NULL,NULL,NULL,NULL,1,NULL,NULL,NULL
14,12113,com.google.android.play.games,Google Play Games,https://lh5.ggpht.com/tkg8ndU21RjzO5WSz7JRpYJ35P-oDTm0md2sNwvVoBtQ0kE_ORHhorrzQWcjVTevxP8_=w300,NULL,Google Inc.,NULL,0,, 1.1.04 ,Entertainment,NULL,NULL,1,NULL,NULL,NULL
15,87853,com.google.android.apps.docs.editors.sheets,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,1,NULL,NULL,NULL
16,87862,com.google.android.apps.photos,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,1,NULL,NULL,NULL
17,87867,com.umfersolutions.eatthiszombies,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,NULL,1,NULL,NULL,NULL
END
谢谢!
最佳答案
您正在将光标位置前进两次，一次
while (cursor.moveToNext())
另一个位于循环末尾
pw.println(line.toString());
cursor.moveToNext();
这就是为什么你总是会得到一半的结果，因为最后你将它移动一个位置，然后在检查 while 条件时它会再次前进，所以它的读取位置 0 ，然后是位置 2，然后是 4...等等...
关于java - Android SQLite游标返回33个结果，但调试仅输出17个，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33374204/