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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 Dr. Xi on June 03, 2010 22:43:43    Last update: June 20, 2010 14:13:05
Using the Sun BASE64Encoder : import java.io.*; import sun.misc.BASE64Encoder... However, the Sun encoder is awfully slow. The Apache encoder is a lot faster. Here's the code with Apache encoder: import java.io.*; import org.apache.commons.cod... Performance comparisons between Apache and Sun: C:\>bash bash-3.2$ time java EncodeFileWithBase...
Created by Dr. Xi on February 09, 2009 23:14:15    Last update: February 09, 2009 23:14:15
This example demonstrates the general steps in creating a custom Java class loader. Normally a class loader would consult its parent class loader when asked to load a class. If it's not loaded by the parent class loader, then the class loader would try to load the class on its own. This class loader tries to load the requested class on its own first, and delegates to the parent only when a java.lang.SecurityException is thrown (which happens when it tries to load core Java classes such as java.lang.String ). The classes are loaded from CLASSPATH through the getResourceAsStream call. It's important to note that when a class is loaded with a certain class loader, all classes referenced from that class are also loaded through the...
Created by Dr. Xi on October 18, 2008 02:59:57    Last update: October 18, 2008 02:59:57
Use java.sql.PreparedStatement to insert a BLOB or CLOB field: void setAsciiStream(int parameterIndex, InputStream x, int length) Sets the designated parameter to the given input stream, which will have the specified number of bytes. void setBinaryStream(int parameterIndex, InputStream x, int length) Sets the designated parameter to the given input stream, which will have the specified number of bytes. void setCharacterStream(int parameterIndex, Reader reader, int length) Sets the designated parameter to the given Reader object, which is the given number of characters long. void setClob(int i, Clob x) Sets the designated parameter to the given Clob object. void setBlob(int i, Blob x) Sets the designated parameter to the given Blob object. Example code: PreparedStatement pstmt = con.prepareStatement...
Created by Dr. Xi on October 18, 2008 02:46:56    Last update: October 18, 2008 02:47:33
There are four pairs of methods in the java.sql.ResultSet class that deal with BLOBs/CLOBs: Reader getCharacterStream(int columnIndex) / Reader getCharacterStream(String columnName) InputStream getBinaryStream(int columnIndex) / InputStream getBinaryStream(String columnName) Blob getBlob(int i) / Blob getBlob(String colName) Clob getClob(int i) / Clob getClob(String colName) Example code: PreparedStatement pstmt = conn.prepareStatemen...