org.eclipse.core.resources.builders扩展点-转载

    org.eclipse.core.resources.builders用于提供一种操作，这种操作可以在IResource改变的时候自动去build,如同改变java文件，会自动进行build，显示错误一样，我们扩展这个builder，并且在自己的项目中使用。我们要做的就是实现build的过程，至于时机由eclipse控制
 
   

   <extension 
         id="builder的ID" 
         name="builder的NAME" 
         point="org.eclipse.core.resources.builders"> 
      <builder 
            hasNature="true"> 
         <run 
               class="builder的CLASS"> 
         </run> 
      </builder> 
   </extension> 
   <extension 
         id="nature的ID" 
         name="nature的NAME" 
         point="org.eclipse.core.resources.natures"> 
      <runtime> 
         <run 
               class="nature的CLASS"> 
         </run> 
      </runtime> 
      <builder 
            id="builder所在的插件ID+.+builder的ID"> 
      </builder> 
   </extension> 

<extension  
         id="builder的ID"  
         name="builder的NAME"  
         point="org.eclipse.core.resources.builders">  
      <builder  
            hasNature="true">  
         <run  
               class="builder的CLASS">  
         </run>  
      </builder>  
   </extension>  
   <extension  
         id="nature的ID"  
         name="nature的NAME"  
         point="org.eclipse.core.resources.natures">  
      <runtime>  
         <run  
               class="nature的CLASS">  
         </run>  
      </runtime>  
      <builder  
            id="builder所在的插件ID+.+builder的ID">  
      </builder>  
   </extension>  

Builder的例子代码：

package project_builder.builder;  
  
import java.util.Map;  
  
import javax.xml.parsers.ParserConfigurationException;  
import javax.xml.parsers.SAXParser;  
import javax.xml.parsers.SAXParserFactory;  
  
import org.eclipse.core.resources.IFile;  
import org.eclipse.core.resources.IMarker;  
import org.eclipse.core.resources.IProject;  
import org.eclipse.core.resources.IResource;  
import org.eclipse.core.resources.IResourceDelta;  
import org.eclipse.core.resources.IResourceDeltaVisitor;  
import org.eclipse.core.resources.IResourceVisitor;  
import org.eclipse.core.resources.IncrementalProjectBuilder;  
import org.eclipse.core.runtime.CoreException;  
import org.eclipse.core.runtime.IProgressMonitor;  
import org.xml.sax.SAXException;  
import org.xml.sax.SAXParseException;  
import org.xml.sax.helpers.DefaultHandler;  
  
public class SampleBuilder extends IncrementalProjectBuilder {  
  
    class SampleDeltaVisitor implements IResourceDeltaVisitor {  
        /* 
         * (non-Javadoc) 
         *  
         * @see org.eclipse.core.resources.IResourceDeltaVisitor#visit(org.eclipse.core.resources.IResourceDelta) 
         */  
        public boolean visit(IResourceDelta delta) throws CoreException {  
            IResource resource = delta.getResource();  
            switch (delta.getKind()) {  
            case IResourceDelta.ADDED:  
                // handle added resource  
                checkXML(resource);  
                break;  
            case IResourceDelta.REMOVED:  
                // handle removed resource  
                break;  
            case IResourceDelta.CHANGED:  
                // handle changed resource  
                checkXML(resource);  
                break;  
            }  
            //return true to continue visiting children.  
            return true;  
        }  
    }  
  
    class SampleResourceVisitor implements IResourceVisitor {  
        public boolean visit(IResource resource) {  
            checkXML(resource);  
            //return true to continue visiting children.  
            return true;  
        }  
    }  
  
    class XMLErrorHandler extends DefaultHandler {  
          
        private IFile file;  
  
        public XMLErrorHandler(IFile file) {  
            this.file = file;  
        }  
  
        private void addMarker(SAXParseException e, int severity) {  
            SampleBuilder.this.addMarker(file, e.getMessage(), e  
                    .getLineNumber(), severity);  
        }  
  
        public void error(SAXParseException exception) throws SAXException {  
            addMarker(exception, IMarker.SEVERITY_ERROR);  
        }  
  
        public void fatalError(SAXParseException exception) throws SAXException {  
            addMarker(exception, IMarker.SEVERITY_ERROR);  
        }  
  
        public void warning(SAXParseException exception) throws SAXException {  
            addMarker(exception, IMarker.SEVERITY_WARNING);  
        }  
    }  
  
    public static final String BUILDER_ID = "Project_Builder.sampleBuilder";  
  
    private static final String MARKER_TYPE = "Project_Builder.xmlProblem";  
  
    private SAXParserFactory parserFactory;  
  
    private void addMarker(IFile file, String message, int lineNumber,  
            int severity) {  
        try {  
            IMarker marker = file.createMarker(MARKER_TYPE);  
            marker.setAttribute(IMarker.MESSAGE, message);  
            marker.setAttribute(IMarker.SEVERITY, severity);  
            if (lineNumber == -1) {  
                lineNumber = 1;  
            }  
            marker.setAttribute(IMarker.LINE_NUMBER, lineNumber);  
        } catch (CoreException e) {  
        }  
    }  
  
    /* 
     * (non-Javadoc) 
     *  
     * @see org.eclipse.core.internal.events.InternalBuilder#build(int, 
     *      java.util.Map, org.eclipse.core.runtime.IProgressMonitor) 
     */  
    protected IProject[] build(int kind, Map args, IProgressMonitor monitor)  
            throws CoreException {  
        if (kind == FULL_BUILD) {  
            fullBuild(monitor);  
        } else {  
            IResourceDelta delta = getDelta(getProject());  
            if (delta == null) {  
                fullBuild(monitor);  
            } else {  
                incrementalBuild(delta, monitor);  
            }  
        }  
        return null;  
    }  
  
    void checkXML(IResource resource) {  
        if (resource instanceof IFile && resource.getName().endsWith(".xml")) {  
            IFile file = (IFile) resource;  
            deleteMarkers(file);  
            XMLErrorHandler reporter = new XMLErrorHandler(file);  
            try {  
                getParser().parse(file.getContents(), reporter);  
            } catch (Exception e1) {  
            }  
        }  
    }  
  
    private void deleteMarkers(IFile file) {  
        try {  
            file.deleteMarkers(MARKER_TYPE, false, IResource.DEPTH_ZERO);  
        } catch (CoreException ce) {  
        }  
    }  
  
    protected void fullBuild(final IProgressMonitor monitor)  
            throws CoreException {  
        try {  
            getProject().accept(new SampleResourceVisitor());  
        } catch (CoreException e) {  
        }  
    }  
  
    private SAXParser getParser() throws ParserConfigurationException,  
            SAXException {  
        if (parserFactory == null) {  
            parserFactory = SAXParserFactory.newInstance();  
        }  
        return parserFactory.newSAXParser();  
    }  
  
    protected void incrementalBuild(IResourceDelta delta,  
            IProgressMonitor monitor) throws CoreException {  
        // the visitor does the work.  
        delta.accept(new SampleDeltaVisitor());  
    }  
}  

Nature的例子代码:

package project_builder.builder; 
 
import org.eclipse.core.resources.ICommand; 
import org.eclipse.core.resources.IProject; 
import org.eclipse.core.resources.IProjectDescription; 
import org.eclipse.core.resources.IProjectNature; 
import org.eclipse.core.runtime.CoreException; 
 
public class SampleNature implements IProjectNature { 
 
    /**
     * ID of this project nature
     */ 
    public static final String NATURE_ID = "Project_Builder.sampleNature"; 
 
    private IProject project; 
 
    /*
     * (non-Javadoc)
     *
     * @see org.eclipse.core.resources.IProjectNature#configure()
     */ 
    public void configure() throws CoreException { 
        IProjectDescription desc = project.getDescription(); 
        ICommand[] commands = desc.getBuildSpec(); 
 
        for (int i = 0; i < commands.length; ++i) { 
            if (commands[i].getBuilderName().equals(SampleBuilder.BUILDER_ID)) { 
                return; 
            } 
        } 
 
        ICommand[] newCommands = new ICommand[commands.length + 1]; 
        System.arraycopy(commands, 0, newCommands, 0, commands.length); 
        ICommand command = desc.newCommand(); 
        command.setBuilderName(SampleBuilder.BUILDER_ID); 
        newCommands[newCommands.length - 1] = command; 
        desc.setBuildSpec(newCommands); 
        project.setDescription(desc, null); 
    } 
 
    /*
     * (non-Javadoc)
     *
     * @see org.eclipse.core.resources.IProjectNature#deconfigure()
     */ 
    public void deconfigure() throws CoreException { 
        IProjectDescription description = getProject().getDescription(); 
        ICommand[] commands = description.getBuildSpec(); 
        for (int i = 0; i < commands.length; ++i) { 
            if (commands[i].getBuilderName().equals(SampleBuilder.BUILDER_ID)) { 
                ICommand[] newCommands = new ICommand[commands.length - 1]; 
                System.arraycopy(commands, 0, newCommands, 0, i); 
                System.arraycopy(commands, i + 1, newCommands, i, 
                        commands.length - i - 1); 
                description.setBuildSpec(newCommands); 
                return; 
            } 
        } 
    } 
 
    /*
     * (non-Javadoc)
     *
     * @see org.eclipse.core.resources.IProjectNature#getProject()
     */ 
    public IProject getProject() { 
        return project; 
    } 
 
    /*
     * (non-Javadoc)
     *
     * @see org.eclipse.core.resources.IProjectNature#setProject(org.eclipse.core.resources.IProject)
     */ 
    public void setProject(IProject project) { 
        this.project = project; 
    } 
 
}