eclispe中查看Android中某个种源码，出现的.class文件中的内容是什么

eclispe中查看Android中某个类源码，出现的.class文件中的内容是什么？
小弟初学Android，想看看Android某些类的源码，下载好源码并在eclipse当中配置好之后，想查看一下一个类的源码，如：SQLiteOpenHelper这个类.按了F3之后，出现的是这样一个文件SQLiteOpenHelper.class
------------------------------------------
文件SQLiteOpenHelper.class内容如下：
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Java code

/*jadclipse*/// Decompiled by Jad v1.5.8g. Copyright 2001 Pavel Kouznetsov.
// Jad home page: http://www.kpdus.com/jad.html
// Decompiler options: packimports(3) radix(10) lradix(10) 
// Source File Name:   SQLiteOpenHelper.java

package android.database.sqlite;

import android.content.Context;

// Referenced classes of package android.database.sqlite:
//            SQLiteDatabase

public abstract class SQLiteOpenHelper
{

    public SQLiteOpenHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version)
    {
        throw new RuntimeException("Stub!");
    }

    public synchronized SQLiteDatabase getWritableDatabase()
    {
        throw new RuntimeException("Stub!");
    }

    public synchronized SQLiteDatabase getReadableDatabase()
    {
        throw new RuntimeException("Stub!");
    }

    public synchronized void close()
    {
        throw new RuntimeException("Stub!");
    }

    public abstract void onCreate(SQLiteDatabase sqlitedatabase);

    public abstract void onUpgrade(SQLiteDatabase sqlitedatabase, int i, int j);

    public void onOpen(SQLiteDatabase db)
    {
        throw new RuntimeException("Stub!");
    }
}


/*
    DECOMPILATION REPORT

    Decompiled from: C:\android-sdk-windows\platforms\android-4\android.jar
    Total time: 16 ms
    Jad reported messages/errors:
    Exit status: 0
    Caught exceptions:
*/

个人理解.class文件不是字节码文件吗？那为什么网上说这里面的就是Android的类的源码了呢？看这个文件里面也没有什么东西啊。

------解决方案--------------------
一般都是这样的啊：

比如：TimePicker这个类。
// Compiled from TimePicker.java (version 1.5 : 49.0, super bit)
public class android.widget.TimePicker extends android.widget.FrameLayout {
  
// Method descriptor #13 (Landroid/content/Context;)V
// Stack: 4, Locals: 2
public TimePicker(android.content.Context context);
0 aload_0 [this]
1 aconst_null
2 checkcast android.content.Context [1]
5 aconst_null
6 checkcast android.util.AttributeSet [2]
9 iconst_0
10 invokespecial android.widget.FrameLayout(android.content.Context, android.util.AttributeSet, int) [3]
13 new java.lang.RuntimeException [4]
16 dup
17 ldc <String "Stub!"> [5]
19 invokespecial java.lang.RuntimeException(java.lang.String) [6]
22 athrow
Line numbers:
[pc: 0, line: 9]
Local variable table:
[pc: 0, pc: 23] local: this index: 0 type: android.widget.TimePicker
[pc: 0, pc: 23] local: context index: 1 type: android.content.Context
  
// Method descriptor #21 (Landroid/content/Context;Landroid/util/AttributeSet;)V
// Stack: 4, Locals: 3
public TimePicker(android.content.Context context, android.util.AttributeSet attrs);
0 aload_0 [this]
1 aconst_null
2 checkcast android.content.Context [1]
5 aconst_null
6 checkcast android.util.AttributeSet [2]
9 iconst_0
10 invokespecial android.widget.FrameLayout(android.content.Context, android.util.AttributeSet, int) [3]
13 new java.lang.RuntimeException [4]
16 dup
17 ldc <String "Stub!"> [5]
19 invokespecial java.lang.RuntimeException(java.lang.String) [6]
22 athrow
Line numbers:
[pc: 0, line: 10]
Local variable table:
[pc: 0, pc: 23] local: this index: 0 type: android.widget.TimePicker