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Created by Dr. Xi on November 11, 2011 10:05:22
Last update: November 11, 2011 10:12:01
This is an HTML image tag filter using Java regex. It takes a string, finds the img tags, replaces the src attribute with one provided by the filter, then adds a class name to the class attribute.
import java.util.regex.*;
import java.io.*;
...
Test file:
<div id="HTML snippet">
<img src="img/big/txt-m...
Created by alfa on July 15, 2011 13:25:45
Last update: July 15, 2011 13:25:45
Read the whole contents of a file into a String. It's better to read the whole file as bytes and convert to String than to read the file line by line and concatenate the lines.
String getFileContents(String fileName) throws...
Using java.nio :
import java.io.FileInputStream;
import java...
Created by alfa on May 04, 2011 12:08:57
Last update: July 15, 2011 12:31:41
To read a whole file at once into a byte array:
File theFile = new File("test.bin");
byte[] byt...
It is important that the total number of bytes read is used for the while condition. Changing the loop to the following may result in an infinite loop !
int m = 0, n = 0;
while (n >= 0) {
n = i...
Created by freyo on May 17, 2011 11:13:17
Last update: May 17, 2011 11:13:17
This is an odd-ball content provider in that it doesn't provide database records, but provides a resource as a stream. It can be used to provide media files or XML resources. Start the project with:
tools/android create project --package com.android... Create assets directory and add an XML file ( assets/demo.xml ): <? xml version="1.0" encoding="UTF-8"?> <people... Edit the layout ( res/layout/main.xml ): <?xml version="1.0" encoding="utf-8"?> <LinearL... Edit src/com/android/cptest/Dummy.java : package com.android.cptest; import java.io.... Add content provider ( src/com/android/cptest/XmlResource.java ): package com.android.cptest; import java.io.... Update AndroidManifest.xml : <?xml version="1.0" encoding="utf-8"?> <manifes... Add this section to the end of build.xml : <target name="-package-resources"> <ech... Build and install: ant install Screenshot: Remove the Dummy activity ( AndroidManifest.xml ): <?xml version="1.0" encoding="utf-8"?> <manifes... Create a new project for...
Created by freyo on April 15, 2011 09:00:54
Last update: April 15, 2011 09:00:54
Sample code for writing to a file in the internal storage. There are three steps:
Open the file with Context.openFileOutput , which returns java.io.FileOutputStream .
Write to the file.
Close the file.
import java.io.*;
import android.content.Contex...
The second parameter to openFileOutput is the operating mode. Available values are:
Context.MODE_PRIVATE
Context.MODE_APPEND
Context.MODE_WORLD_READABLE
Context.MODE_WORLD_WRITEABLE
The file is saved in /data/data/<package_name>/files .
Created by nogeek on April 07, 2011 20:54:17
Last update: April 07, 2011 20:54:17
Use javax.xml.parsers.DocumentBuilder to parse xml. DocumentBuilder.parse() takes:
java.io.File
org.xml.sax.InputSource
java.io.InputStream
java.lang.String as a URI to an XML document
Example code:
import java.io.*;
import javax.xml.parsers.Docu...
Created by alfa on April 06, 2011 12:48:44
Last update: April 06, 2011 12:48:44
package com.demo.io;
import java.io.*;
...
Created by Dr. Xi on March 29, 2011 16:06:57
Last update: April 01, 2011 12:33:52
This utility class retrieves SSL certificates from the server and print them out to the stdout. The output can be saved to a file and imported to a Java keystore. This is useful in your test environment where the SSL certificate is self-signed.
import java.io.InputStream;
import java.io.Outp...
Retrieve and import the a certificate:
E:\test>java RetrieveSSLCert 192.168.69.144 8081 >...
Created by Dr. Xi on January 14, 2010 00:28:27
Last update: March 30, 2011 15:37:44
A task that a Java developer does so frequently is to find out where a certain class can be found - to resolve compilation errors, classpath issues, or version conflicts of the same class introduced by multiple class loaders. A long while back I wrote a simple Perl script to perform the task. Later I was informed that there are Swing based Jar Browser and Jars Browser . Then, there are a couple of shell one-liners:
# one liner 1 find -name "*.jar" -print0 | xarg... But all of them share the same problem: if a class is in a jar nested in another jar, it cannot be found. Such is the case for a class inside a jar under the WEB-INF/lib directory of a...
Created by Dr. Xi on March 30, 2011 13:43:05
Last update: March 30, 2011 13:45:27
Method 1 - use javap with verbose flag:
$ javap HelloWorld -verbose | head
Compiled fro...
Method 2 - use a utility class:
import java.io.*;
import java.nio.ByteBuffer;
...
According to the VM Spec , a Java class file has this structure:
ClassFile {
u4 magic;
...