Android example source code file (DefaultDataHandler.java)

This example Android source code file (DefaultDataHandler.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, arg, attributes, contentinserthandler, contentresolver, contentvalues, inputstream, io, ioexception, net, network, postfix, row, sax, saxexception, select, stack, string, uri, util

The DefaultDataHandler.java Android example source code

/*
 * Copyright (C) 2008 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.content;

import android.net.Uri;
import android.util.Xml;

import org.xml.sax.Attributes;
import org.xml.sax.Locator;
import org.xml.sax.SAXException;

import java.io.IOException;
import java.io.InputStream;
import java.util.Stack;

/**
 * Inserts default data from InputStream, should be in XML format.
 * If the provider syncs data to the server, the imported data will be synced to the server.
 * <p>Samples:

 * <br/>
 *  Insert one row:
 * <pre>
 * <row uri="content://contacts/people">
 *  <Col column = "name" value = "foo feebe "/>
 *  <Col column = "addr" value = "Tx"/>
 * </row></pre>
 * <br/>
 * Delete, it must be in order of uri, select, and arg:
 * <pre>
 * <del uri="content://contacts/people" select="name=? and addr=?" 
 *  arg1 = "foo feebe" arg2 ="Tx"/></pre>
 * <br/>
 *  Use first row's uri to insert into another table,
 *  content://contacts/people/1/phones:
 * <pre>
 * <row uri="content://contacts/people">
 *  <col column = "name" value = "foo feebe"/>
 *  <col column = "addr" value = "Tx"/>
 *  <row postfix="phones">
 *    <col column="number" value="512-514-6535"/>
 *  </row>
 *  <row postfix="phones">
 *    <col column="cell" value="512-514-6535"/>
 *  </row>  
 * </row></pre>
 * <br/>
 *  Insert multiple rows in to same table and same attributes:
 * <pre>
 * <row uri="content://contacts/people" >
 *  <row>
 *   <col column= "name" value = "foo feebe"/>
 *   <col column= "addr" value = "Tx"/>
 *  </row>
 *  <row>
 *  </row>
 * </row></pre>
 *
 * @hide
 */ 
public class DefaultDataHandler implements ContentInsertHandler {
    private final static String ROW = "row";
    private final static String COL = "col";
    private final static String URI_STR = "uri";
    private final static String POSTFIX = "postfix";
    private final static String DEL = "del";
    private final static String SELECT = "select";
    private final static String ARG = "arg";   
   
    private Stack<Uri> mUris = new Stack();
    private ContentValues mValues;
    private ContentResolver mContentResolver;   
    
    public void insert(ContentResolver contentResolver, InputStream in)
            throws IOException, SAXException {
        mContentResolver = contentResolver;
        Xml.parse(in, Xml.Encoding.UTF_8, this);
    }
    
    public void insert(ContentResolver contentResolver, String in)
        throws SAXException {
        mContentResolver = contentResolver;
        Xml.parse(in, this);
    }
    
    private void parseRow(Attributes atts) throws SAXException {
        String uriStr = atts.getValue(URI_STR);
        Uri uri;
        if (uriStr != null) {
            // case 1
            uri = Uri.parse(uriStr);
            if (uri == null) {
                throw new SAXException("attribute " +
                        atts.getValue(URI_STR) + " parsing failure"); 
            }
            
        } else if (mUris.size() > 0){
            // case 2
            String postfix = atts.getValue(POSTFIX);
            if (postfix != null) {
                uri = Uri.withAppendedPath(mUris.lastElement(),
                        postfix);
            } else {
                uri = mUris.lastElement();
            } 
        } else {
            throw new SAXException("attribute parsing failure"); 
        }
        
        mUris.push(uri);
        
    }
    
    private Uri insertRow() {
        Uri u = mContentResolver.insert(mUris.lastElement(), mValues);
        mValues = null;
        return u;
    }
    
    public void startElement(String uri, String localName, String name,
            Attributes atts) throws SAXException {
        if (ROW.equals(localName)) {            
            if (mValues != null) {
                // case 2, <Col> before  insert last uri
                if (mUris.empty()) {
                    throw new SAXException("uri is empty");
                }
                Uri nextUri = insertRow();
                if (nextUri == null) {
                    throw new SAXException("insert to uri " + 
                            mUris.lastElement().toString() + " failure");
                } else {
                    // make sure the stack lastElement save uri for more than one row
                    mUris.pop();
                    mUris.push(nextUri);
                    parseRow(atts);
                }
            } else {
                int attrLen = atts.getLength();
                if (attrLen == 0) {
                    // case 3, share same uri as last level
                    mUris.push(mUris.lastElement());
                } else {
                    parseRow(atts);
                }
            }                
        } else if (COL.equals(localName)) {
            int attrLen = atts.getLength();
            if (attrLen != 2) {
                throw new SAXException("illegal attributes number " + attrLen);
            }
            String key = atts.getValue(0);
            String value = atts.getValue(1);
            if (key != null && key.length() > 0 && value != null && value.length() > 0) {
                if (mValues == null) {
                    mValues = new ContentValues();
                }
                mValues.put(key, value);
            } else {
                throw new SAXException("illegal attributes value");
            }            
        } else if (DEL.equals(localName)){
            Uri u = Uri.parse(atts.getValue(URI_STR));
            if (u == null) {
                throw new SAXException("attribute " +
                        atts.getValue(URI_STR) + " parsing failure"); 
            }
            int attrLen = atts.getLength() - 2;
            if (attrLen > 0) {
                String[] selectionArgs = new String[attrLen];
                for (int i = 0; i < attrLen; i++) {
                    selectionArgs[i] = atts.getValue(i+2);
                }
                mContentResolver.delete(u, atts.getValue(1), selectionArgs);
            } else if (attrLen == 0){
                mContentResolver.delete(u, atts.getValue(1), null);
            } else {
                mContentResolver.delete(u, null, null);
            }
            
        } else {
            throw new SAXException("unknown element: " + localName);
        }
    }
    
    public void endElement(String uri, String localName, String name)
            throws SAXException {
        if (ROW.equals(localName)) {
            if (mUris.empty()) {
                throw new SAXException("uri mismatch"); 
            }
            if (mValues != null) {
                insertRow();
            }
            mUris.pop();                
        } 
    }


    public void characters(char[] ch, int start, int length)
            throws SAXException {
        // TODO Auto-generated method stub

    }

    public void endDocument() throws SAXException {
        // TODO Auto-generated method stub

    }

    public void endPrefixMapping(String prefix) throws SAXException {
        // TODO Auto-generated method stub

    }

    public void ignorableWhitespace(char[] ch, int start, int length)
            throws SAXException {
        // TODO Auto-generated method stub

    }

    public void processingInstruction(String target, String data)
            throws SAXException {
        // TODO Auto-generated method stub

    }

    public void setDocumentLocator(Locator locator) {
        // TODO Auto-generated method stub

    }

    public void skippedEntity(String name) throws SAXException {
        // TODO Auto-generated method stub

    }

    public void startDocument() throws SAXException {
        // TODO Auto-generated method stub

    }

    public void startPrefixMapping(String prefix, String uri)
            throws SAXException {
        // TODO Auto-generated method stub

    }
    
}