com.github.ferstl.depgraph.HelpMojo Maven / Gradle / Ivy
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This Maven plugin generates dependency graphs on single modules or in an aggregated form
on multimodule projects. The graphs are represented by .dot files. In case that Graphviz
is installed on the machine where this plugin is run, the .dot file can be directly converted
into all supported image files.
package com.github.ferstl.depgraph;
import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugins.annotations.Mojo;
import org.apache.maven.plugins.annotations.Parameter;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
/**
* Display help information on depgraph-maven-plugin.
* Call mvn depgraph:help -Ddetail=true -Dgoal=<goal-name> to display parameter details.
* @author maven-plugin-tools
*/
@Mojo( name = "help", requiresProject = false, threadSafe = true )
public class HelpMojo
extends AbstractMojo
{
/**
* If true, display all settable properties for each goal.
*
*/
@Parameter( property = "detail", defaultValue = "false" )
private boolean detail;
/**
* The name of the goal for which to show help. If unspecified, all goals will be displayed.
*
*/
@Parameter( property = "goal" )
private java.lang.String goal;
/**
* The maximum length of a display line, should be positive.
*
*/
@Parameter( property = "lineLength", defaultValue = "80" )
private int lineLength;
/**
* The number of spaces per indentation level, should be positive.
*
*/
@Parameter( property = "indentSize", defaultValue = "2" )
private int indentSize;
// groupId/artifactId/plugin-help.xml
private static final String PLUGIN_HELP_PATH =
"/META-INF/maven/com.github.ferstl/depgraph-maven-plugin/plugin-help.xml";
private static final int DEFAULT_LINE_LENGTH = 80;
private Document build()
throws MojoExecutionException
{
getLog().debug( "load plugin-help.xml: " + PLUGIN_HELP_PATH );
InputStream is = null;
try
{
is = getClass().getResourceAsStream( PLUGIN_HELP_PATH );
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
return dBuilder.parse( is );
}
catch ( IOException e )
{
throw new MojoExecutionException( e.getMessage(), e );
}
catch ( ParserConfigurationException e )
{
throw new MojoExecutionException( e.getMessage(), e );
}
catch ( SAXException e )
{
throw new MojoExecutionException( e.getMessage(), e );
}
finally
{
if ( is != null )
{
try
{
is.close();
}
catch ( IOException e )
{
throw new MojoExecutionException( e.getMessage(), e );
}
}
}
}
/**
* {@inheritDoc}
*/
public void execute()
throws MojoExecutionException
{
if ( lineLength <= 0 )
{
getLog().warn( "The parameter 'lineLength' should be positive, using '80' as default." );
lineLength = DEFAULT_LINE_LENGTH;
}
if ( indentSize <= 0 )
{
getLog().warn( "The parameter 'indentSize' should be positive, using '2' as default." );
indentSize = 2;
}
Document doc = build();
StringBuilder sb = new StringBuilder();
Node plugin = getSingleChild( doc, "plugin" );
String name = getValue( plugin, "name" );
String version = getValue( plugin, "version" );
String id = getValue( plugin, "groupId" ) + ":" + getValue( plugin, "artifactId" ) + ":" + version;
if ( isNotEmpty( name ) && !name.contains( id ) )
{
append( sb, name + " " + version, 0 );
}
else
{
if ( isNotEmpty( name ) )
{
append( sb, name, 0 );
}
else
{
append( sb, id, 0 );
}
}
append( sb, getValue( plugin, "description" ), 1 );
append( sb, "", 0 );
//plugin
String goalPrefix = getValue( plugin, "goalPrefix" );
Node mojos1 = getSingleChild( plugin, "mojos" );
List mojos = findNamedChild( mojos1, "mojo" );
if ( goal == null || goal.length() <= 0 )
{
append( sb, "This plugin has " + mojos.size() + ( mojos.size() > 1 ? " goals:" : " goal:" ), 0 );
append( sb, "", 0 );
}
for ( Node mojo : mojos )
{
writeGoal( sb, goalPrefix, (Element) mojo );
}
if ( getLog().isInfoEnabled() )
{
getLog().info( sb.toString() );
}
}
private static boolean isNotEmpty( String string )
{
return string != null && string.length() > 0;
}
private String getValue( Node node, String elementName )
throws MojoExecutionException
{
return getSingleChild( node, elementName ).getTextContent();
}
private Node getSingleChild( Node node, String elementName )
throws MojoExecutionException
{
List namedChild = findNamedChild( node, elementName );
if ( namedChild.isEmpty() )
{
throw new MojoExecutionException( "Could not find " + elementName + " in plugin-help.xml" );
}
if ( namedChild.size() > 1 )
{
throw new MojoExecutionException( "Multiple " + elementName + " in plugin-help.xml" );
}
return namedChild.get( 0 );
}
private List findNamedChild( Node node, String elementName )
{
List result = new ArrayList();
NodeList childNodes = node.getChildNodes();
for ( int i = 0; i < childNodes.getLength(); i++ )
{
Node item = childNodes.item( i );
if ( elementName.equals( item.getNodeName() ) )
{
result.add( item );
}
}
return result;
}
private Node findSingleChild( Node node, String elementName )
throws MojoExecutionException
{
List elementsByTagName = findNamedChild( node, elementName );
if ( elementsByTagName.isEmpty() )
{
return null;
}
if ( elementsByTagName.size() > 1 )
{
throw new MojoExecutionException( "Multiple " + elementName + "in plugin-help.xml" );
}
return elementsByTagName.get( 0 );
}
private void writeGoal( StringBuilder sb, String goalPrefix, Element mojo )
throws MojoExecutionException
{
String mojoGoal = getValue( mojo, "goal" );
Node configurationElement = findSingleChild( mojo, "configuration" );
Node description = findSingleChild( mojo, "description" );
if ( goal == null || goal.length() <= 0 || mojoGoal.equals( goal ) )
{
append( sb, goalPrefix + ":" + mojoGoal, 0 );
Node deprecated = findSingleChild( mojo, "deprecated" );
if ( ( deprecated != null ) && isNotEmpty( deprecated.getTextContent() ) )
{
append( sb, "Deprecated. " + deprecated.getTextContent(), 1 );
if ( detail && description != null )
{
append( sb, "", 0 );
append( sb, description.getTextContent(), 1 );
}
}
else if ( description != null )
{
append( sb, description.getTextContent(), 1 );
}
append( sb, "", 0 );
if ( detail )
{
Node parametersNode = getSingleChild( mojo, "parameters" );
List parameters = findNamedChild( parametersNode, "parameter" );
append( sb, "Available parameters:", 1 );
append( sb, "", 0 );
for ( Node parameter : parameters )
{
writeParameter( sb, parameter, configurationElement );
}
}
}
}
private void writeParameter( StringBuilder sb, Node parameter, Node configurationElement )
throws MojoExecutionException
{
String parameterName = getValue( parameter, "name" );
String parameterDescription = getValue( parameter, "description" );
Element fieldConfigurationElement = (Element) findSingleChild( configurationElement, parameterName );
String parameterDefaultValue = "";
if ( fieldConfigurationElement != null && fieldConfigurationElement.hasAttribute( "default-value" ) )
{
parameterDefaultValue = " (Default: " + fieldConfigurationElement.getAttribute( "default-value" ) + ")";
}
append( sb, parameterName + parameterDefaultValue, 2 );
Node deprecated = findSingleChild( parameter, "deprecated" );
if ( ( deprecated != null ) && isNotEmpty( deprecated.getTextContent() ) )
{
append( sb, "Deprecated. " + deprecated.getTextContent(), 3 );
append( sb, "", 0 );
}
append( sb, parameterDescription, 3 );
if ( "true".equals( getValue( parameter, "required" ) ) )
{
append( sb, "Required: Yes", 3 );
}
if ( ( fieldConfigurationElement != null ) && isNotEmpty( fieldConfigurationElement.getTextContent() ) )
{
String property = getPropertyFromExpression( fieldConfigurationElement.getTextContent() );
append( sb, "User property: " + property, 3 );
}
append( sb, "", 0 );
}
/**
* Repeat a String n times to form a new string.
*
* @param str String to repeat
* @param repeat number of times to repeat str
* @return String with repeated String
* @throws NegativeArraySizeException if repeat < 0
* @throws NullPointerException if str is null
*/
private static String repeat( String str, int repeat )
{
StringBuilder buffer = new StringBuilder( repeat * str.length() );
for ( int i = 0; i < repeat; i++ )
{
buffer.append( str );
}
return buffer.toString();
}
/**
* Append a description to the buffer by respecting the indentSize and lineLength parameters.
* Note: The last character is always a new line.
*
* @param sb The buffer to append the description, not null.
* @param description The description, not null.
* @param indent The base indentation level of each line, must not be negative.
*/
private void append( StringBuilder sb, String description, int indent )
{
for ( String line : toLines( description, indent, indentSize, lineLength ) )
{
sb.append( line ).append( '\n' );
}
}
/**
* Splits the specified text into lines of convenient display length.
*
* @param text The text to split into lines, must not be null.
* @param indent The base indentation level of each line, must not be negative.
* @param indentSize The size of each indentation, must not be negative.
* @param lineLength The length of the line, must not be negative.
* @return The sequence of display lines, never null.
* @throws NegativeArraySizeException if indent < 0
*/
private static List toLines( String text, int indent, int indentSize, int lineLength )
{
List lines = new ArrayList();
String ind = repeat( "\t", indent );
String[] plainLines = text.split( "(\r\n)|(\r)|(\n)" );
for ( String plainLine : plainLines )
{
toLines( lines, ind + plainLine, indentSize, lineLength );
}
return lines;
}
/**
* Adds the specified line to the output sequence, performing line wrapping if necessary.
*
* @param lines The sequence of display lines, must not be null.
* @param line The line to add, must not be null.
* @param indentSize The size of each indentation, must not be negative.
* @param lineLength The length of the line, must not be negative.
*/
private static void toLines( List lines, String line, int indentSize, int lineLength )
{
int lineIndent = getIndentLevel( line );
StringBuilder buf = new StringBuilder( 256 );
String[] tokens = line.split( " +" );
for ( String token : tokens )
{
if ( buf.length() > 0 )
{
if ( buf.length() + token.length() >= lineLength )
{
lines.add( buf.toString() );
buf.setLength( 0 );
buf.append( repeat( " ", lineIndent * indentSize ) );
}
else
{
buf.append( ' ' );
}
}
for ( int j = 0; j < token.length(); j++ )
{
char c = token.charAt( j );
if ( c == '\t' )
{
buf.append( repeat( " ", indentSize - buf.length() % indentSize ) );
}
else if ( c == '\u00A0' )
{
buf.append( ' ' );
}
else
{
buf.append( c );
}
}
}
lines.add( buf.toString() );
}
/**
* Gets the indentation level of the specified line.
*
* @param line The line whose indentation level should be retrieved, must not be null.
* @return The indentation level of the line.
*/
private static int getIndentLevel( String line )
{
int level = 0;
for ( int i = 0; i < line.length() && line.charAt( i ) == '\t'; i++ )
{
level++;
}
for ( int i = level + 1; i <= level + 4 && i < line.length(); i++ )
{
if ( line.charAt( i ) == '\t' )
{
level++;
break;
}
}
return level;
}
private String getPropertyFromExpression( String expression )
{
if ( expression != null && expression.startsWith( "${" ) && expression.endsWith( "}" )
&& !expression.substring( 2 ).contains( "${" ) )
{
// expression="${xxx}" -> property="xxx"
return expression.substring( 2, expression.length() - 1 );
}
// no property can be extracted
return null;
}
}