J2ME:rms的事件监听器

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本文介绍J2ME中RMS（Record Management System）的事件监听器使用方法，通过继承RecordListener接口并实现recordAdded、recordChanged和recordDeleted方法来响应记录的添加、更改和删除事件。

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其实j2me中的rms的事件监听器很简单，主要是继承RecordListener接口，实现其中的三个方法：

recordAdded(RecordStore rs, int rid); //添加记录响应事件

recordChanged(RecordStore rs, int rid); //改变记录响应事件

recordDeleted(RecordStore rs, int rid); //删除记录响应事件

例子：

import javax.microedition.midlet.*; import javax.microedition.rms.*; public class RecordListenerExample extends MIDlet implements RecordListener { RecordStore rs1 = null; RecordStore rs2 = null; public RecordListenerExample() { } public void startApp() throws MIDletStateChangeException { // open two Record Stores try { rs1 = RecordStore.openRecordStore("test1 ", true); rs1.addRecordListener(this); } catch (Exception e) { } try { rs2 = RecordStore.openRecordStore("test2 ", true); } catch (Exception e) { } // add two records to rs1 byte data[] = new byte[4]; for (int j = 0; j < 2; j++) { try { int i = rs1.getNextRecordID(); data[0] = (byte) ((i >> 24) & 0xff); data[1] = (byte) ((i >> 16) & 0xff); data[2] = (byte) ((i >> 8) & 0xff); data[3] = (byte) (i & 0xff); System.out.println("record #" + rs1.addRecord(data, 0, 4) + " is added to Record Store 1 "); } catch (Exception e) { } } // modified the second last added record try { int id = rs1.getNextRecordID() - 2; data = rs1.getRecord(id); data[0] += 1; rs1.setRecord(id, data, 0, 4); System.out.println("record #" + id + " of Record Store 1 is modified.."); } catch (Exception e) { } // delete the last added try { int id = rs1.getNextRecordID() - 1; rs1.deleteRecord(id); System.out.println("record #" + id + " of Record Store 1 is deleted.."); } catch (Exception e) { } // end // destroyApp(true); // notifyDestroyed(); } public void pauseApp() { } public void destroyApp(boolean unconditional) { // close the two Record Stores try { if (rs1 != null) rs1.closeRecordStore(); } catch (Exception e) { } try { if (rs2 != null) rs2.closeRecordStore(); } catch (Exception e) { } } // implement RecordListener public void recordAdded(RecordStore rs, int rid) { if (rs == rs1) { try { byte data[] = rs.getRecord(rid); int id = rs2.addRecord(data, 0, data.length); System.out.println("record #" + id + " is added to Record Store 2.."); } catch (Exception e) { } } } public void recordChanged(RecordStore rs, int rid) { if (rs == rs1) { try { byte data[] = rs.getRecord(rid); rs2.setRecord(rid, data, 0, data.length); System.out.println("record #" + rid + " of Record Store 2 is modified.."); } catch (Exception e) { } } } public void recordDeleted(RecordStore rs, int rid) { if (rs == rs1) { try { rs2.deleteRecord(rid); System.out.println("record #" + rid + " of Record Store 2 is deleted.."); } catch (Exception e) { } } } }