X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Forg%2Fyaz4j%2FResultSet.java;h=aef52f641eb8531bcf97e5839fa67d0b65d6d85c;hb=80fe126a86a610466bdc4089f10e17fd3e683d44;hp=b70a03e94076b3938aaf4e45876f2953adc2af6e;hpb=428d895d6dc31b784e953ea935d662cfc4a4bd43;p=yaz4j-moved-to-github.git

diff --git a/src/main/java/org/yaz4j/ResultSet.java b/src/main/java/org/yaz4j/ResultSet.java
index b70a03e..aef52f6 100644
--- a/src/main/java/org/yaz4j/ResultSet.java
+++ b/src/main/java/org/yaz4j/ResultSet.java
@@ -1,66 +1,125 @@
 package org.yaz4j;
 
-import org.yaz4j.jni.SWIGTYPE_p_ZOOM_connection_p;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import org.yaz4j.exception.ZoomException;
 import org.yaz4j.jni.SWIGTYPE_p_ZOOM_record_p;
 import org.yaz4j.jni.SWIGTYPE_p_ZOOM_resultset_p;
 import org.yaz4j.jni.yaz4jlib;
 
-public class ResultSet
-{
-	private SWIGTYPE_p_ZOOM_resultset_p resultSet;	
-	private SWIGTYPE_p_ZOOM_connection_p connection;
-	private long size = 0 ;
-	private Record[] records = null ;
-	private boolean disposed = false;	
-	
-	ResultSet(SWIGTYPE_p_ZOOM_resultset_p resultSet, SWIGTYPE_p_ZOOM_connection_p connection)
-	{
-		this.resultSet = resultSet ;
-		this.connection = connection ;
-		size = yaz4jlib.ZOOM_resultset_size(this.resultSet);
-		records = new Record[(int)size];
-	}
-	
-	public void finalize()
-	{
-		this.Dispose();		
-	}	
+/**
+ * This class represents a "buffered handle" to the result set created on the
+ * server and thus retrieving records may invlove a request to the server if
+ * those records are not locally cached. Details on how to configure the retrieval
+ * (present) process are available in the YAZ manual
+ *
+ * @see <a href="http://www.indexdata.com/yaz/doc/zoom.resultsets.html">YAZ ZOOM result sets</a>
+ *
+ * Becacuse of the server misbehaviour or errors during retrieval the
+ * "getRecord" method may either return null or throw exceptions, even when the
+ * index of retrieved records lies within the bounds of the set. Client
+ * code should be prepared for such situations.
+ *
+ * This class implements the iterable interface and as such can be used within
+ * foreach loops, it's important to note however that in this case the errors
+ * during retrieval will be masked with standard NoSuchElementExceptions
+ *
+ * @author jakub
+ */
+public class ResultSet implements Iterable<Record> {
+  //for GC refcount
 
-    ResultSetOptionsCollection getResultSetOptions()
-    {
-    	return new ResultSetOptionsCollection(resultSet);
+  private Connection conn;
+  private SWIGTYPE_p_ZOOM_resultset_p resultSet;
+  private long size = 0;
+  private boolean disposed = false;
+
+  ResultSet(SWIGTYPE_p_ZOOM_resultset_p resultSet, Connection conn) {
+    this.resultSet = resultSet;
+    size = yaz4jlib.ZOOM_resultset_size(this.resultSet);
+    this.conn = conn;
+  }
+
+  @Override
+  public void finalize() {
+    this._dispose();
+  }
+
+  /**
+   * Read option by name.
+   * @param name option name
+   * @return option value
+   */
+  public String option(String name) {
+    return yaz4jlib.ZOOM_resultset_option_get(resultSet, name);
+  }
+
+  /**
+   * Write option with a given name.
+   * @param name option name
+   * @param value option value
+   * @return result set (self) for chainability
+   */
+  public ResultSet option(String name, String value) {
+    yaz4jlib.ZOOM_resultset_option_set(resultSet, name, value);
+    return this;
+  }
+
+  public Record getRecord(long index) throws ZoomException {
+    SWIGTYPE_p_ZOOM_record_p record =
+      yaz4jlib.ZOOM_resultset_record(resultSet, index);
+    //may be out of range or unsupported syntax
+    if (record == null) {
+      return null;
+    }
+    int errorCode = yaz4jlib.ZOOM_record_error(record, null, null, null);
+    if (errorCode != 0) {
+      throw new ZoomException("Record excpetion, code " + errorCode);
     }
-	
-	public Record getRecord(int index)
-	{
-		if ( records[index] == null)
-		{
-			SWIGTYPE_p_ZOOM_record_p recordTemp = yaz4jlib.ZOOM_resultset_record(resultSet, index);
-			records[index] = new Record(recordTemp, this);
-		}
-	
-		return this.records[index];
-	}
-	
-	public int getSize()
-	{
-		return (int)size ;
-	}
-	
-	public void Dispose()
-	{
-		if (! disposed )
-		{
-			for( int i=0 ; i<records.length ; i++)
-			{
-				if (records[i] != null)
-					records[i].Dispose();
-			}
+    return new Record(record, this);
+  }
 
-			yaz4jlib.ZOOM_resultset_destroy(resultSet);
-			connection = null;
-			resultSet = null;
-			disposed = true;
-		}
-	}
+  @Override
+  public Iterator<Record> iterator() {
+    return new Iterator<Record>() {
+      private long cur;
+      @Override
+      public boolean hasNext() {
+        return cur < size;
+      }
+
+      @Override
+      public Record next() {
+        try {
+          return getRecord(cur++);
+        } catch (ZoomException ze) {
+          throw new NoSuchElementException(ze.getMessage());
+        }
+      }
+
+      @Override
+      public void remove() {
+        throw new UnsupportedOperationException("remove operation not supported");
+      }
+    };
+  }
+
+  public ResultSet sort(String type, String spec) throws ZoomException {
+    int ret = yaz4jlib.ZOOM_resultset_sort1(resultSet, type, spec);
+    if (ret != 0) throw new ZoomException("Sorting resultset failed");
+    return this;
+  }
+
+  public long getHitCount() {
+    return size;
+  }
+
+  void _dispose() {
+    if (!disposed) {
+      yaz4jlib.ZOOM_resultset_destroy(resultSet);
+      resultSet = null;
+      conn = null;
+      disposed = true;
+    }
+  }
 }