【Android】Tips for Android developer: “Conversion to Dalvik format failed: Unable to execute dex: null”

Androiddeveloper, I have met a strange problem when I want use a third party jar, it remained me that:
Dex Loader] Unable to execute dex: null
Conversion to Dalvik format failed: Unable to execute dex: null
out ofmemoryerror…An internal error occurred during: “Build Project”.
Java heap space

This is the DEX Error，I find the solutions by Google, one way is to modify the eclipse.ini, you can increase the memory allocated in eclipse.ini to this: -Xms128m -Xmx512m or something higher, but this didn’t work for me. After modify the eclipse.ini, I cannot start the eclipse. By StackOverflow, I find a solution:

eclipse.ini file must have -vm on first line and path on second line. don’t try to put everything into one line!
-vm
C:\Program Files\Java\jdk1.6.0_07\bin\javaw.exe

After add the -vm and the path in my eclipse.ini, I can start my Eclipse and the problem has been resolved.

大致解释一下上面的：

问题：

eclipse在build project的时候Conversion to Dalvik format failed: Unable to execute dex: null

解决：

在eclipse目录下打开eclipse.ini，在第一行添加

-vm
D:\Program Files\Java\jdk1.6.0_12\bin\javaw.exe

之后修改

-Xms64m
-Xms128m
为

-Xms128m
-Xmx512m

Another way to solve the ” Conversion to Dalvik format failed: Unable to execute dex: null” problem is using the user library, the concrete steps are as follows:
1. Right-click the project in Eclipse and select “Build Path -> Add Libraries…”.
2. Select User Library from the list and click Next.
3. Click the “User Libraries…” button.
4. Click “New…” in the User Libraries dialog.
5. Give the user library a name and select the System library checkbox and click OK.
6. Highlight the newly added user library in the list and click the “Add JARs…” button and add the desiredjar files.
7. Click OK on the User Libraries dialog.
8. Make sure the new user library is checked in the Add Library dialog and …