javacodehighlighter.java

Jive是基于JSP/JAVA技术构架的一个大型BBS论坛系统,这是Jive论坛2.6版本的源程序

package com.jivesoftware.forum.filter;

import java.io.*;

import com.jivesoftware.util.*;
import com.jivesoftware.forum.*;
import com.jivesoftware.util.JavaCodeViewer;

/**
 * A ForumMessageFilter that syntax highlights Java code appearing between
 * [code][/code] tags in the body of ForumMessage.
 */
public class JavaCodeHighlighter extends ForumMessageFilter {

    private String commentStart;
    private String commentEnd;
    private String stringStart;
    private String stringEnd;
    private String reservedWordStart;
    private String reservedWordEnd;
    private String methodStart;
    private String methodEnd;
    private String characterStart;
    private String characterEnd;
    private String bracketStart;
    private String bracketEnd;
    private String numberStart;
    private String numberEnd;
    private boolean filterMethod;
    private boolean filterNumber;

    // for formatting code with an html table and printing line numbers
    private boolean applyTableSurround;            // surround code with an html table
    private boolean showLineCount;                 // show line numbers
    private static final int ALIGNLEFT = 0;        // left-side alignment
    private static final int ALIGNRIGHT = 1;       // right-side alignment
    // private int alignPosition;
    private String tableBorderColor;
    private String tableLinePanelBackgroundColor;
    private String tableCodePanelBackgroundColor;
    private String lineNumberColor;

    /**
     * Much of the work of this filter is done by a JavaCodeViewer object.
     */
    private JavaCodeViewer viewer;

    /**
     * Construct a new JavaCodeHighlighter filter.
     */
    public JavaCodeHighlighter() {
        viewer = new JavaCodeViewer();
        commentStart = viewer.getCommentStart();
        commentEnd = viewer.getCommentEnd();
        stringStart = viewer.getStringStart();
        stringEnd = viewer.getStringEnd();
        reservedWordStart = viewer.getReservedWordStart();
        reservedWordEnd = viewer.getReservedWordEnd();
        methodStart = viewer.getMethodStart();
        methodEnd = viewer.getMethodEnd();
        characterStart = viewer.getCharacterStart();
        characterEnd = viewer.getCharacterEnd();
        bracketStart = viewer.getBracketStart();
        bracketEnd = viewer.getBracketEnd();
        numberStart = viewer.getNumberStart();
        numberEnd = viewer.getNumberEnd();
        filterMethod = viewer.getFilterMethod();
        filterNumber = viewer.getFilterNumber();
        applyTableSurround = false;          // default
        showLineCount = false;               // default
        tableBorderColor = "#999999";       // default
        tableLinePanelBackgroundColor = "#dddddd";    // default
        tableCodePanelBackgroundColor = "#ffffff";    // default
        lineNumberColor = "#555555";        // default
    }

    /**
     * Clones a new filter that will have the same properties and that
     * will wrap around the specified message.
     *
     * @param message the ForumMessage to wrap the new filter around.
     */
    public ForumMessageFilter clone(ForumMessage message) {
        JavaCodeHighlighter filter = new JavaCodeHighlighter();
        filter.message = message;
        filter.setCommentStart(commentStart);
        filter.setCommentEnd(commentEnd);
        filter.setStringStart(stringStart);
        filter.setStringEnd(stringEnd);
        filter.setReservedWordStart(reservedWordStart);
        filter.setReservedWordEnd(reservedWordEnd);
        filter.setMethodStart(methodStart);
        filter.setMethodEnd(methodEnd);
        filter.setCharacterStart(characterStart);
        filter.setCharacterEnd(characterEnd);
        filter.setBracketStart(bracketStart);
        filter.setBracketEnd(bracketEnd);
        filter.setNumberStart(numberStart);
        filter.setNumberEnd(numberEnd);
        filter.setFilterMethod(filterMethod);
        filter.setFilterNumber(filterNumber);
        filter.setApplyTableSurround(applyTableSurround);
        filter.setShowLineCount(showLineCount);
        filter.setTableBorderColor(tableBorderColor);
        filter.setTableLinePanelBackgroundColor(tableLinePanelBackgroundColor);
        filter.setTableCodePanelBackgroundColor(tableCodePanelBackgroundColor);
        filter.setLineNumberColor(lineNumberColor);
        return filter;
    }

    //FROM FORUMMESSAGEFILTER//

    public boolean isCacheable() {
        return true;
    }

    //FROM THE FORUMMESSAGE INTERFACE//

    /**
     * <b>Overloaded</b> to return the body of message with Java code between
     * [code] [/code] tags syntax highlighted.
     */
    public String getBody() {
        // if(true) {
        if(applyTableSurround) {
            return highlightCode(message.getBody(), true);
        }
        else {
            return highlightCode(message.getBody(), false);
        }
    }

    /**
     * create an outter table that surrounds code.
     * A benefit of this is that the table background colors
     * can be specified according to whatever maybe easier on
     * the eyes, especially if the existing page's background color
     * does not display well with formatted code.
     * Another useful feature of the code table is the ability to
     * conveniently output line numbers.
     * @param text code already formatted with html makeup
     * @param numLines number of lines in text
     * @return code surrounded with a table, possibly displaying line numbers
     */
    private String surroundWithTable(String text, int numLines) {
        // kludgey, non-optimized code, as the table
        // code can be shared across all calls to the filter
        StringBuffer buffer = new StringBuffer();
        buffer.append("<table border=\"0\" cellspacing=\"1\" cellpadding=\"3\" ");
        buffer.append("bgcolor=\"").append(tableBorderColor).append("\">");
        buffer.append("<tr>");
        // if line counts should be displayed
        // a cool feature to implement would be to be able
        // to specify left or right sides
        if(showLineCount) {
            buffer.append("<td width=\"1\" align=\"left\" ");
            buffer.append(" bgcolor=\"").append(tableLinePanelBackgroundColor);
            buffer.append("\" valign=\"top\">");
            buffer.append("<font color=\"").append(lineNumberColor).append("\">");
            buffer.append("<pre>");
            buffer.append(makeLines(numLines));
            buffer.append("</pre>");
            buffer.append("</font>");
            buffer.append("</td>");
        }
        buffer.append("<td align=\"left\" ");
        buffer.append("bgcolor=\"").append(tableCodePanelBackgroundColor);
        buffer.append("\" valign=\"top\">");
        buffer.append("<pre>");
        buffer.append(text);
        buffer.append("</pre>");
        buffer.append("</td>").append("</tr>");
        buffer.append("</table>");
        return buffer.toString();
    }

    /**
     * create line numbers
     * the effect is similar to an ide's line number display
     */
    private String makeLines(int numLines) {
        StringBuffer buffer = new StringBuffer();
        for(int i=1; i<=numLines; i++) {
/*
            // saving bandwidth at the cost of computation!
            if(i==numLines) {
                buffer.append(i+" \n");
            }
            else {
                buffer.append(i+"\n");
            }
*/
            buffer.append(i + "<br>");
        }
        return buffer.toString();
    }

    //OTHER METHODS//

    public boolean getApplyTableSurround() {
        return applyTableSurround;
    }

    public void setApplyTableSurround(boolean applyTableSurround) {
        this.applyTableSurround = applyTableSurround;
    }

    public boolean getShowLineCount() {
        return showLineCount;
    }

    public void setShowLineCount(boolean showLineCount) {
        this.showLineCount = showLineCount;
    }
    /**
     * Returns the code table's border color. For example, it could
     * be <code>red</code> or <code>#123456</code>
     *
     * @return the code table's border color.
     */
    public String getTableBorderColor() {
        return tableBorderColor;
    }

    /**
     * Sets the code table's border color. For example, it could be
     * <code>red</code> or <code>#123456</code>
     *
     * @param tableBorderColor the code table's border color.
     */
    public void setTableBorderColor(String tableBorderColor) {
        this.tableBorderColor = tableBorderColor;
    }

    /**
     * Returns the line-number panel's background color. For example, it could
     * be <code>white</code> or <code>#123456</code>
     *
     * @return the line panel's background color.
     */
    public String getTableLinePanelBackgroundColor() {
        return tableLinePanelBackgroundColor;
    }

    /**
     * Sets the line-number panel's background color. For example, it could be
     * <code>white</code> or <code>#123456</code>
     *
     * @param tableLinePanelBackgroundColor the line panel's background color.
     */
    public void setTableLinePanelBackgroundColor(String tableLinePanelBackgroundColor) {
        this.tableLinePanelBackgroundColor = tableLinePanelBackgroundColor;
    }

    /**
     * Returns the code panel's background color. For example, it could be
     * <code>blue</code> or <code>#123456</code>
     *
     * @return the code panel's background color.
     */
    public String getTableCodePanelBackgroundColor() {
        return tableCodePanelBackgroundColor;
    }

    /**
     * Sets the code panel's background color. For example, it could be
     * <code>blue</code> or <code>#123456</code>
     *
     * @param tableCodePanelBackgroundColor the code panel's background color.
     */
    public void setTableCodePanelBackgroundColor(String tableCodePanelBackgroundColor) {
        this.tableCodePanelBackgroundColor = tableCodePanelBackgroundColor;
    }

    public String getLineNumberColor() {
        return lineNumberColor;
    }

    public void setLineNumberColor(String lineNumberColor) {
        this.lineNumberColor = lineNumberColor;
    }

    /**
     * Returns the HTML tag that starts comment blocks. For example, it could
     * be <code>&lt;i&gt;</code>.
     *
     * @return the HTML tag to start comment blocks.
     */
    public String getCommentStart() {
        return commentStart;
    }

    /**
     * Sets the HTML tag that starts comment blocks. For example, it could be
     * <code>&lt;i&gt;</code>.
     *
     * @param commentStart the HTML tag to start comment blocks.
     */
    public void setCommentStart(String commentStart) {
        this.commentStart = commentStart;
        viewer.setCommentStart(commentStart);
    }

    /**
     * Returns the HTML tag that ends comment blocks. For example, it could
     * be <code>&lt;/i&gt;</code>. The tag should correspond to the comment
     * start tag.
     *
     * @return the HTML tag to end comment blocks.
     */
    public String getCommentEnd() {
        return commentEnd;
    }

    /**
     * Sets the HTML tag that ends comment blocks. For example, it could be
     * <code>&lt;/i&gt;</code>. The tag should correspond to the comment
     * start tag.
     *
     * @param commentEnd the HTML tag to end comment blocks.
     */
    public void setCommentEnd(String commentEnd) {
        this.commentEnd = commentEnd;
        viewer.setCommentEnd(commentEnd);
    }

    /**
     * Returns the HTML tag that starts string blocks. For example, it could
     * be <code>&lt;font color=&quot;red&quot;&gt;</code>.
     *
     * @return the HTML tag to start string blocks.
     */
    public String getStringStart() {
        return stringStart;
    }

    /**
     * Sets the HTML tag that starts string blocks. For example, it could be
     * <code>&lt;font color=&quot;red&quot;&gt;</code>.
     *
     * @param stringStart the HTML tag to start string blocks.
     */
    public void setStringStart(String stringStart) {
        this.stringStart = stringStart;
        viewer.setStringStart(stringStart);
    }

    /**
     * Returns the HTML tag that ends string blocks. For example, it could be
     * <code>&lt;/font&gt;</code>. The tag should correspond to the string 
     * start tag.
     *
     * @return the HTML tag to end string blocks.
     */
    public String getStringEnd() {
        return stringEnd;
    }

    /**
     * Sets the HTML tag that ends string blocks. For example, it could be
     * <code>&lt;/font&gt;</code>.  The tag should correspond to the string
     * end tag.
     *
     * @param stringEnd the HTML tag to end string blocks.
     */
    public void setStringEnd(String stringEnd) {
        this.stringEnd = stringEnd;
        viewer.setStringEnd(stringEnd);
    }

    /**
     * Returns the HTML tag that starts keyword blocks. For example, it could be
     * <code>&lt;font color=&quot;navy&quot;&gt;</code>.
     *
     * @return the HTML tag to start keyword blocks.
     */
    public String getReservedWordStart() {
        return reservedWordStart;
    }

    /**
     * Sets the HTML tag that starts reserved word blocks. For example, it could be
     * <code>&lt;font color=&quot;navy&quot;&gt;</code>.
     *
     * @param reservedWordStart the HTML tag to start keyword blocks.
     */
    public void setReservedWordStart(String reservedWordStart) {
        this.reservedWordStart = reservedWordStart;
        viewer.setReservedWordStart(reservedWordStart);
    }

    /**
     * Returns the HTML tag that ends keyword blocks. For example, it could be
     * <code>&lt;/font&gt;</code>.  This should correspond to the start tag for
     * keyword blocks.
     *
     * @return the HTML tag to end keyword blocks.
     */
    public String getReservedWordEnd() {
        return reservedWordEnd;
    }

    /**
     * Sets the HTML tag that ends keyword blocks. For example, it could be
     * <code>&lt;font color=&quot;navy&quot;&gt;</code>.  This should 
     * correspond to the start tag for keyword blocks.
     *
     * @param reservedWordEnd the HTML tag to end keyword blocks.
     */
    public void setReservedWordEnd(String reservedWordEnd) {
        this.reservedWordEnd = reservedWordEnd;
        viewer.setReservedWordEnd(reservedWordEnd);
    }

    /**
     * Returns the HTML tag that starts method blocks. For example, it could be