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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 Dr. Xi on October 26, 2010 16:07:40    Last update: October 26, 2010 16:07:40
This is a more generic version, which can be expanded to accommodate additional file signatures. import java.io.*; import java.util.*; pu...
Created by Dr. Xi on July 19, 2010 21:58:34    Last update: July 23, 2010 21:37:23
Parsing XML in Java is really simple: import java.io.*; import javax.xml.parsers.Docu... The parser implementation details are hidden behind the JAXP API. In case you want to know which parser implementation is used, this is what the JavaDoc for DocumentBuilderFactory.newInstance says: Use the javax.xml.parsers.DocumentBuilderFactory system property. Use the properties file " lib/jaxp.properties " in the JRE directory. This configuration file is in standard java.util.Properties format and contains the fully qualified name of the implementation class with the key being the system property defined above. The jaxp.properties file is read only once by the JAXP implementation and it's values are then cached for future use. If the file does not exist when the first attempt is made to read from it, no further attempts are made to...
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...