How to Use jar files for eclipse-based Android Projects

This blog is based on Eclipse 3.6.2, JDK 1.6, Android
2.1 practice.

1. Create a Java Project

 

Code

package com.zhang;public class Party {private String name;public void setName(String name) {this.name = name;}public String getName() {return name;}public String startParty() {return name + " starts happy!";}}

2. Export JAR File

Right-click the Java project name and select Export

Next

Directly click Next to finish. The highparty. jar file is generated under/home/mark/desktop.

3. Create an android Project

4. Import jar files

Create a new folder named libs in the veryparty project.

Copy the highparty. jar file to the libs directory.

Right-click the veryparty project and choose build path/Add External Archives/

Then select libs/highparty. Jar

Last Android code:

package com.net.veryplay;import com.zhang.Party;import android.os.Bundle;import android.app.Activity;import android.widget.TextView;public class MainActivity extends Activity {private TextView tv;@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);setupViews();}@Overrideprotected void onResume() {super.onResume();try {Class.forName("com.zhang.Party");Party party = new Party();party.setName("mark");tv.setText(party.startParty());} catch (ClassNotFoundException e) {tv.setText("Oops... no content!");}}private void setupViews() {tv = (TextView) findViewById(R.id.tv);}}

5. Run

The APK generated after eclipse compilation contains the JAR file code.

You can still see the JAR file code through decompilation.

Finally, we would like to remind the general public that:

InStep 4The folder name is libs. Do not name it lib or another name. Otherwise, it will be difficult to add a jar file.

If you don't believe it, you can try it! (The following errors may occur)

If you have any questions, leave a message!