X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Forg%2Fyaz4j%2FResultSet.java;h=b2fd11958beb65d303f0ceef91cf1afcf7cfa3e3;hb=8c7413fbaf0870975229e8e101f79096b5dfe6f0;hp=fad095c019f0836f70575f46bc5639fded42f990;hpb=2def7bc64faa1dfb9f3393f2c2ef0bca0c6265e1;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 fad095c..b2fd119 100644
--- a/src/main/java/org/yaz4j/ResultSet.java
+++ b/src/main/java/org/yaz4j/ResultSet.java
@@ -1,57 +1,166 @@
 package org.yaz4j;
 
-import org.yaz4j.jni.SWIGTYPE_p_ZOOM_connection_p;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+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.SWIGTYPE_p_p_ZOOM_record_p;
 import org.yaz4j.jni.yaz4jlib;
 
-public class ResultSet {
+/**
+ * This class represents a "buffered handle" to the result set created on the
+ * server and thus retrieving records may involve 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>
+ *
+ * Because of server misbehavior 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
 
-    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;
+  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, SWIGTYPE_p_ZOOM_connection_p connection) {
-        this.resultSet = resultSet;
-        this.connection = connection;
-        size = yaz4jlib.ZOOM_resultset_size(this.resultSet);
-        records = new Record[(int) size];
-    }
+  ResultSet(SWIGTYPE_p_ZOOM_resultset_p resultSet, Connection conn) {
+    this.resultSet = resultSet;
+    size = yaz4jlib.ZOOM_resultset_size(this.resultSet);
+    this.conn = conn;
+  }
 
-    public void finalize() {
-        this.dispose();
-    }
+  @Override
+  public void finalize() {
+    this._dispose();
+  }
 
-    ResultSetOptionsCollection getResultSetOptions() {
-        return new ResultSetOptionsCollection(resultSet);
-    }
+  /**
+   * Read option by name.
+   * @param name option name
+   * @return option value
+   */
+  public String option(String name) {
+    return yaz4jlib.ZOOM_resultset_option_get(resultSet, name);
+  }
 
-    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);
-        }
+  /**
+   * 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;
+  }
 
-        return this.records[index];
+  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;
     }
-
-    public int getSize() {
-        return (int) size;
+    int errorCode = yaz4jlib.ZOOM_record_error(record, null, null, null);
+    if (errorCode != 0) {
+      throw new ZoomException("Record excpetion, code " + errorCode);
+    }
+    return new Record(record, this);
+  }
+  
+  /**
+   * Retrieve a collection of records at once. If a record cannot be retrieved,
+   * it is omitted from the list (thus the list size may be smaller than 'count').
+   * @param start start index within the result set
+   * @param count number of records to retrieve
+   * @return
+   * @throws ZoomException raised in case of protocol errors
+   */
+  public List<Record> getRecords(long start, int count) throws ZoomException {
+    List<Record> out = new ArrayList<Record>(count);
+    SWIGTYPE_p_p_ZOOM_record_p recs = yaz4jlib.new_zoomRecordArray(count);
+    yaz4jlib.ZOOM_resultset_records(resultSet, recs, start, count);
+    ZoomException err = this.conn.getZoomException();
+    if (err != null) { 
+      throw err;
     }
+    for (int i = 0; i < count; i++) {
+      SWIGTYPE_p_ZOOM_record_p record =
+        yaz4jlib.zoomRecordArray_getitem(recs, i);
+      if (record == null) {
+        continue;
+      }
+      int errorCode = yaz4jlib.ZOOM_record_error(record, null, null, null);
+      if (errorCode != 0) {
+        throw new ZoomException("Record excpetion, code " + errorCode);
+      }
+      out.add(new Record(record, this));
+    }
+    return out;
+  }
+
+  @Override
+  public Iterator<Record> iterator() {
+    return new Iterator<Record>() {
+      private long cur;
+      @Override
+      public boolean hasNext() {
+        return cur < size;
+      }
 
-    public void dispose() {
-        if (!disposed) {
-            for (int i = 0; i < records.length; i++) {
-                if (records[i] != null) {
-                    records[i].dispose();
-                }
-            }
-            yaz4jlib.ZOOM_resultset_destroy(resultSet);
-            connection = null;
-            resultSet = null;
-            disposed = true;
+      @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");
+      }
+    };
+  }
+
+  /**
+   * 
+   * @param type
+   * @param spec
+   * @return
+   * @throws ZoomException 
+   */
+  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;
     }
+  }
 }