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Tomcat example source code file (Parameters.java)

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

Java - Tomcat tags/keywords

bytechunk, charchunk, charchunk, enumeration, hashtable, io, ioexception, ioexception, messagebytes, mimeheaders, parameters, parameters, string, string, udecoder, util

The Tomcat Parameters.java source code

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 org.apache.tomcat.util.http;

import java.io.IOException;
import java.util.Enumeration;
import java.util.Hashtable;

import org.apache.tomcat.util.buf.ByteChunk;
import org.apache.tomcat.util.buf.CharChunk;
import org.apache.tomcat.util.buf.MessageBytes;
import org.apache.tomcat.util.buf.UDecoder;
import org.apache.tomcat.util.collections.MultiMap;

/**
 * 
 * @author Costin Manolache
 */
public final class Parameters extends MultiMap {

    
    private static org.apache.juli.logging.Log log=
        org.apache.juli.logging.LogFactory.getLog(Parameters.class );
    
    // Transition: we'll use the same Hashtable( String->String[] )
    // for the beginning. When we are sure all accesses happen through
    // this class - we can switch to MultiMap
    private Hashtable<String,String[]> paramHashStringArray =
        new Hashtable<String,String[]>();
    private boolean didQueryParameters=false;
    private boolean didMerge=false;
    
    MessageBytes queryMB;
    MimeHeaders  headers;

    UDecoder urlDec;
    MessageBytes decodedQuery=MessageBytes.newInstance();
    
    public static final int INITIAL_SIZE=4;

    // Garbage-less parameter merging.
    // In a sub-request with parameters, the new parameters
    // will be stored in child. When a getParameter happens,
    // the 2 are merged togheter. The child will be altered
    // to contain the merged values - the parent is allways the
    // original request.
    private Parameters child=null;
    private Parameters parent=null;
    private Parameters currentChild=null;

    String encoding=null;
    String queryStringEncoding=null;
    
    /**
     * 
     */
    public Parameters() {
        super( INITIAL_SIZE );
    }

    public void setQuery( MessageBytes queryMB ) {
        this.queryMB=queryMB;
    }

    public void setHeaders( MimeHeaders headers ) {
        this.headers=headers;
    }

    public void setEncoding( String s ) {
        encoding=s;
        if(debug>0) log( "Set encoding to " + s );
    }

    public void setQueryStringEncoding( String s ) {
        queryStringEncoding=s;
        if(debug>0) log( "Set query string encoding to " + s );
    }

    public void recycle() {
        super.recycle();
        paramHashStringArray.clear();
        didQueryParameters=false;
        currentChild=null;
        didMerge=false;
        encoding=null;
        decodedQuery.recycle();
    }
    
    // -------------------- Sub-request support --------------------

    public Parameters getCurrentSet() {
        if( currentChild==null )
            return this;
        return currentChild;
    }
    
    /** Create ( or reuse ) a child that will be used during a sub-request.
        All future changes ( setting query string, adding parameters )
        will affect the child ( the parent request is never changed ).
        Both setters and getters will return the data from the deepest
        child, merged with data from parents.
    */
    public void push() {
        // We maintain a linked list, that will grow to the size of the
        // longest include chain.
        // The list has 2 points of interest:
        // - request.parameters() is the original request and head,
        // - request.parameters().currentChild() is the current set.
        // The ->child and parent<- links are preserved ( currentChild is not
        // the last in the list )
        
        // create a new element in the linked list
        // note that we reuse the child, if any - pop will not
        // set child to null !
        if( currentChild==null ) {
            currentChild=new Parameters();
            currentChild.setURLDecoder( urlDec );
            currentChild.parent=this;
            return;
        }
        if( currentChild.child==null ) {
            currentChild.child=new Parameters();
            currentChild.setURLDecoder( urlDec );
            currentChild.child.parent=currentChild;
        } // it is not null if this object already had a child
        // i.e. a deeper include() ( we keep it )

        // the head will be the new element.
        currentChild=currentChild.child;
        currentChild.setEncoding( encoding );
    }

    /** Discard the last child. This happens when we return from a
        sub-request and the parameters are locally modified.
     */
    public void pop() {
        if( currentChild==null ) {
            throw new RuntimeException( "Attempt to pop without a push" );
        }
        currentChild.recycle();
        currentChild=currentChild.parent;
        // don't remove the top.
    }
    
    // -------------------- Data access --------------------
    // Access to the current name/values, no side effect ( processing ).
    // You must explicitely call handleQueryParameters and the post methods.
    
    // This is the original data representation ( hash of String->String[])

    public void addParameterValues( String key, String[] newValues) {
        if ( key==null ) return;
        String values[];
        if (paramHashStringArray.containsKey(key)) {
            String oldValues[] = (String[])paramHashStringArray.get(key);
            values = new String[oldValues.length + newValues.length];
            for (int i = 0; i < oldValues.length; i++) {
                values[i] = oldValues[i];
            }
            for (int i = 0; i < newValues.length; i++) {
                values[i+ oldValues.length] = newValues[i];
            }
        } else {
            values = newValues;
        }

        paramHashStringArray.put(key, values);
    }

    public String[] getParameterValues(String name) {
        handleQueryParameters();
        // sub-request
        if( currentChild!=null ) {
            currentChild.merge();
            return (String[])currentChild.paramHashStringArray.get(name);
        }

        // no "facade"
        String values[]=(String[])paramHashStringArray.get(name);
        return values;
    }
 
    public Enumeration getParameterNames() {
        handleQueryParameters();
        // Slow - the original code
        if( currentChild!=null ) {
            currentChild.merge();
            return currentChild.paramHashStringArray.keys();
        }

        // merge in child
        return paramHashStringArray.keys();
    }

    /** Combine the parameters from parent with our local ones
     */
    private void merge() {
        // recursive
        if( debug > 0 ) {
            log("Before merging " + this + " " + parent + " " + didMerge );
            log(  paramsAsString());
        }
        // Local parameters first - they take precedence as in spec.
        handleQueryParameters();

        // we already merged with the parent
        if( didMerge ) return;

        // we are the top level
        if( parent==null ) return;

        // Add the parent props to the child ( lower precedence )
        parent.merge();
        Hashtable<String,String[]> parentProps=parent.paramHashStringArray;
        merge2( paramHashStringArray , parentProps);
        didMerge=true;
        if(debug > 0 )
            log("After " + paramsAsString());
    }


    // Shortcut.
    public String getParameter(String name ) {
        String[] values = getParameterValues(name);
        if (values != null) {
            if( values.length==0 ) return "";
            return values[0];
        } else {
            return null;
        }
    }
    // -------------------- Processing --------------------
    /** Process the query string into parameters
     */
    public void handleQueryParameters() {
        if( didQueryParameters ) return;

        didQueryParameters=true;

        if( queryMB==null || queryMB.isNull() )
            return;
        
        if( debug > 0  )
            log( "Decoding query " + decodedQuery + " " + queryStringEncoding);

        try {
            decodedQuery.duplicate( queryMB );
        } catch (IOException e) {
            // Can't happen, as decodedQuery can't overflow
            e.printStackTrace();
        }
        processParameters( decodedQuery, queryStringEncoding );
    }

    // --------------------
    
    /** Combine 2 hashtables into a new one.
     *  ( two will be added to one ).
     *  Used to combine child parameters ( RequestDispatcher's query )
     *  with parent parameters ( original query or parent dispatcher )
     */
    private static void merge2(Hashtable<String,String[]> one,
            Hashtable<String,String[]> two ) {
        Enumeration e = two.keys();

        while (e.hasMoreElements()) {
            String name = (String) e.nextElement();
            String[] oneValue = one.get(name);
            String[] twoValue = two.get(name);
            String[] combinedValue;

            if (twoValue == null) {
                continue;
            } else {
                if( oneValue==null ) {
                    combinedValue = new String[twoValue.length];
                    System.arraycopy(twoValue, 0, combinedValue,
                                     0, twoValue.length);
                } else {
                    combinedValue = new String[oneValue.length +
                                               twoValue.length];
                    System.arraycopy(oneValue, 0, combinedValue, 0,
                                     oneValue.length);
                    System.arraycopy(twoValue, 0, combinedValue,
                                     oneValue.length, twoValue.length);
                }
                one.put(name, combinedValue);
            }
        }
    }

    // incredibly inefficient data representation for parameters,
    // until we test the new one
    private void addParam( String key, String value ) {
        if( key==null ) return;
        String values[];
        if (paramHashStringArray.containsKey(key)) {
            String oldValues[] = (String[])paramHashStringArray.
                get(key);
            values = new String[oldValues.length + 1];
            for (int i = 0; i < oldValues.length; i++) {
                values[i] = oldValues[i];
            }
            values[oldValues.length] = value;
        } else {
            values = new String[1];
            values[0] = value;
        }
        
        
        paramHashStringArray.put(key, values);
    }

    public void setURLDecoder( UDecoder u ) {
        urlDec=u;
    }

    // -------------------- Parameter parsing --------------------

    // This code is not used right now - it's the optimized version
    // of the above.

    // we are called from a single thread - we can do it the hard way
    // if needed
    ByteChunk tmpName=new ByteChunk();
    ByteChunk tmpValue=new ByteChunk();
    CharChunk tmpNameC=new CharChunk(1024);
    CharChunk tmpValueC=new CharChunk(1024);
    
    public void processParameters( byte bytes[], int start, int len ) {
        processParameters(bytes, start, len, encoding);
    }

    public void processParameters( byte bytes[], int start, int len, 
                                   String enc ) {
        int end=start+len;
        int pos=start;
        
        if( debug>0 ) 
            log( "Bytes: " + new String( bytes, start, len ));

        do {
            boolean noEq=false;
            int valStart=-1;
            int valEnd=-1;
            
            int nameStart=pos;
            int nameEnd=ByteChunk.indexOf(bytes, nameStart, end, '=' );
            // Workaround for a&b&c encoding
            int nameEnd2=ByteChunk.indexOf(bytes, nameStart, end, '&' );
            if( (nameEnd2!=-1 ) &&
                ( nameEnd==-1 || nameEnd > nameEnd2) ) {
                nameEnd=nameEnd2;
                noEq=true;
                valStart=nameEnd;
                valEnd=nameEnd;
                if( debug>0) log("no equal " + nameStart + " " + nameEnd + " " + new String(bytes, nameStart, nameEnd-nameStart) );
            }
            if( nameEnd== -1 ) 
                nameEnd=end;

            if( ! noEq ) {
                valStart= (nameEnd < end) ? nameEnd+1 : end;
                valEnd=ByteChunk.indexOf(bytes, valStart, end, '&');
                if( valEnd== -1 ) valEnd = (valStart < end) ? end : valStart;
            }
            
            pos=valEnd+1;
            
            if( nameEnd<=nameStart ) {
                log.warn("Parameters: Invalid chunk ignored.");
                continue;
                // invalid chunk - it's better to ignore
            }
            tmpName.setBytes( bytes, nameStart, nameEnd-nameStart );
            tmpValue.setBytes( bytes, valStart, valEnd-valStart );

            try {
                addParam( urlDecode(tmpName, enc), urlDecode(tmpValue, enc) );
            } catch (IOException e) {
                // Exception during character decoding: skip parameter
                log.warn("Parameters: Character decoding failed. " + 
                         "Parameter skipped.", e);
            }

            tmpName.recycle();
            tmpValue.recycle();

        } while( pos<end );
    }

    private String urlDecode(ByteChunk bc, String enc)
        throws IOException {
        if( urlDec==null ) {
            urlDec=new UDecoder();   
        }
        urlDec.convert(bc);
        String result = null;
        if (enc != null) {
            bc.setEncoding(enc);
            result = bc.toString();
        } else {
            CharChunk cc = tmpNameC;
            int length = bc.getLength();
            cc.allocate(length, -1);
            // Default encoding: fast conversion
            byte[] bbuf = bc.getBuffer();
            char[] cbuf = cc.getBuffer();
            int start = bc.getStart();
            for (int i = 0; i < length; i++) {
                cbuf[i] = (char) (bbuf[i + start] & 0xff);
            }
            cc.setChars(cbuf, 0, length);
            result = cc.toString();
            cc.recycle();
        }
        return result;
    }

    public void processParameters( char chars[], int start, int len ) {
        int end=start+len;
        int pos=start;
        
        if( debug>0 ) 
            log( "Chars: " + new String( chars, start, len ));
        do {
            boolean noEq=false;
            int nameStart=pos;
            int valStart=-1;
            int valEnd=-1;
            
            int nameEnd=CharChunk.indexOf(chars, nameStart, end, '=' );
            int nameEnd2=CharChunk.indexOf(chars, nameStart, end, '&' );
            if( (nameEnd2!=-1 ) &&
                ( nameEnd==-1 || nameEnd > nameEnd2) ) {
                nameEnd=nameEnd2;
                noEq=true;
                valStart=nameEnd;
                valEnd=nameEnd;
                if( debug>0) log("no equal " + nameStart + " " + nameEnd + " " + new String(chars, nameStart, nameEnd-nameStart) );
            }
            if( nameEnd== -1 ) nameEnd=end;
            
            if( ! noEq ) {
                valStart= (nameEnd < end) ? nameEnd+1 : end;
                valEnd=CharChunk.indexOf(chars, valStart, end, '&');
                if( valEnd== -1 ) valEnd = (valStart < end) ? end : valStart;
            }
            
            pos=valEnd+1;
            
            if( nameEnd<=nameStart ) {
                continue;
                // invalid chunk - no name, it's better to ignore
                // XXX log it ?
            }
            
            try {
                tmpNameC.append( chars, nameStart, nameEnd-nameStart );
                tmpValueC.append( chars, valStart, valEnd-valStart );

                if( debug > 0 )
                    log( tmpNameC + "= " + tmpValueC);

                if( urlDec==null ) {
                    urlDec=new UDecoder();   
                }

                urlDec.convert( tmpNameC );
                urlDec.convert( tmpValueC );

                if( debug > 0 )
                    log( tmpNameC + "= " + tmpValueC);
                
                addParam( tmpNameC.toString(), tmpValueC.toString() );
            } catch( IOException ex ) {
                ex.printStackTrace();
            }

            tmpNameC.recycle();
            tmpValueC.recycle();

        } while( pos<end );
    }
    
    public void processParameters( MessageBytes data ) {
        processParameters(data, encoding);
    }

    public void processParameters( MessageBytes data, String encoding ) {
        if( data==null || data.isNull() || data.getLength() <= 0 ) return;

        if( data.getType() == MessageBytes.T_BYTES ) {
            ByteChunk bc=data.getByteChunk();
            processParameters( bc.getBytes(), bc.getOffset(),
                               bc.getLength(), encoding);
        } else {
            if (data.getType()!= MessageBytes.T_CHARS ) 
                data.toChars();
            CharChunk cc=data.getCharChunk();
            processParameters( cc.getChars(), cc.getOffset(),
                               cc.getLength());
        }
    }

    /** Debug purpose
     */
    public String paramsAsString() {
        StringBuffer sb=new StringBuffer();
        Enumeration en= paramHashStringArray.keys();
        while( en.hasMoreElements() ) {
            String k=(String)en.nextElement();
            sb.append( k ).append("=");
            String v[]=(String[])paramHashStringArray.get( k );
            for( int i=0; i<v.length; i++ )
                sb.append( v[i] ).append(",");
            sb.append("\n");
        }
        return sb.toString();
    }

    private static int debug=0;
    private void log(String s ) {
        if (log.isDebugEnabled())
            log.debug("Parameters: " + s );
    }
   
    // -------------------- Old code, needs rewrite --------------------
    
    /** Used by RequestDispatcher
     */
    public void processParameters( String str ) {
        int end=str.length();
        int pos=0;
        if( debug > 0)
            log("String: " + str );
        
        do {
            boolean noEq=false;
            int valStart=-1;
            int valEnd=-1;
            
            int nameStart=pos;
            int nameEnd=str.indexOf('=', nameStart );
            int nameEnd2=str.indexOf('&', nameStart );
            if( nameEnd2== -1 ) nameEnd2=end;
            if( (nameEnd2!=-1 ) &&
                ( nameEnd==-1 || nameEnd > nameEnd2) ) {
                nameEnd=nameEnd2;
                noEq=true;
                valStart=nameEnd;
                valEnd=nameEnd;
                if( debug>0) log("no equal " + nameStart + " " + nameEnd + " " + str.substring(nameStart, nameEnd) );
            }

            if( nameEnd== -1 ) nameEnd=end;

            if( ! noEq ) {
                valStart=nameEnd+1;
                valEnd=str.indexOf('&', valStart);
                if( valEnd== -1 ) valEnd = (valStart < end) ? end : valStart;
            }
            
            pos=valEnd+1;
            
            if( nameEnd<=nameStart ) {
                continue;
            }
            if( debug>0)
                log( "XXX " + nameStart + " " + nameEnd + " "
                     + valStart + " " + valEnd );
            
            try {
                tmpNameC.append(str, nameStart, nameEnd-nameStart );
                tmpValueC.append(str, valStart, valEnd-valStart );
            
                if( debug > 0 )
                    log( tmpNameC + "= " + tmpValueC);

                if( urlDec==null ) {
                    urlDec=new UDecoder();   
                }

                urlDec.convert( tmpNameC );
                urlDec.convert( tmpValueC );

                if( debug > 0 )
                    log( tmpNameC + "= " + tmpValueC);
                
                addParam( tmpNameC.toString(), tmpValueC.toString() );
            } catch( IOException ex ) {
                ex.printStackTrace();
            }

            tmpNameC.recycle();
            tmpValueC.recycle();

        } while( pos<end );
    }


}

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