initial commit for a new layout.

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@969 71c3de6d-444a-0410-be80-ed276b4c234a

core/src/main/java/hudson/XmlFile.java

@@ -0,0 +1,97 @@
+package hudson;
+
+import com.thoughtworks.xstream.XStream;
+import com.thoughtworks.xstream.converters.ConversionException;
+import com.thoughtworks.xstream.io.StreamException;
+import com.thoughtworks.xstream.io.xml.XppReader;
+import hudson.util.AtomicFileWriter;
+import hudson.util.IOException2;
+import hudson.util.XStream2;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+
+/**
+ * Represents an XML data file that Hudson uses as a data file.
+ *
+ * @author Kohsuke Kawaguchi
+ */
+public final class XmlFile {
+    private final XStream xs;
+    private final File file;
+
+    public XmlFile(File file) {
+        this(DEFAULT_XSTREAM,file);
+    }
+
+    public XmlFile(XStream xs, File file) {
+        this.xs = xs;
+        this.file = file;
+    }
+
+    /**
+     * Loads the contents of this file into a new object.
+     */
+    public Object read() throws IOException {
+        Reader r = new BufferedReader(new InputStreamReader(new FileInputStream(file), "UTF-8"));
+        try {
+            return xs.fromXML(r);
+        } catch(StreamException e) {
+            throw new IOException2("Unable to read "+file,e);
+        } catch(ConversionException e) {
+            throw new IOException2("Unable to read "+file,e);
+        } finally {
+            r.close();
+        }
+    }
+
+    /**
+     * Loads the contents of this file into an existing object.
+     */
+    public void unmarshal( Object o ) throws IOException {
+        Reader r = new BufferedReader(new InputStreamReader(new FileInputStream(file),"UTF-8"));
+        try {
+            xs.unmarshal(new XppReader(r),o);
+        } catch (StreamException e) {
+            throw new IOException2(e);
+        } catch(ConversionException e) {
+            throw new IOException2("Unable to read "+file,e);
+        } finally {
+            r.close();
+        }
+    }
+
+    public void write( Object o ) throws IOException {
+        AtomicFileWriter w = new AtomicFileWriter(file);
+        try {
+            w.write("<?xml version='1.0' encoding='UTF-8'?>\n");
+            xs.toXML(o,w);
+            w.commit();
+        } catch(StreamException e) {
+            throw new IOException2(e);
+        } finally {
+            w.close();
+        }
+    }
+
+    public boolean exists() {
+        return file.exists();
+    }
+
+    public void mkdirs() {
+        file.getParentFile().mkdirs();
+    }
+
+    public String toString() {
+        return file.toString();
+    }
+
+    /**
+     * {@link XStream} instance is supposed to be thread-safe.
+     */
+    private static final XStream DEFAULT_XSTREAM = new XStream2();
+}