simplesearch.java

这是j2me的例子,可供初学者学习,里面有源代码,是我写的

package com.tan.rs;
/*
 * SimpleSearch.java
 *
 * Created on 2007年4月3日, 上午10:15
 */

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.rms.RecordEnumeration;
import javax.microedition.rms.RecordStore;
import javax.microedition.rms.RecordStoreException;
import javax.microedition.rms.RecordStoreNotOpenException;

/**
 *
 * @author  USER
 * @version
 */
public class SimpleSearch extends MIDlet implements CommandListener{ 
    Display display = null;
    private Form fmMain;
    private Command exit;
    private Command find;
    private TextField tfFind;
    private RecordStore rs = null;
    private String rec_store = "db_6";
    private StringItem siMatch;
    
    public void startApp() {
        display.setCurrent(fmMain);
    }
    
    public void pauseApp() {
    }
    
    public void destroyApp(boolean unconditional) {
        closeRecStrore();
    }

    public void commandAction(Command command, Displayable displayable) {
        if(command == exit)
        {
            destroyApp(true);
            notifyDestroyed();
        }
        else if(command == find)
        {
            searchRecordStore();
        }
    }

    private void openRecStore() {
        try {
            rs = RecordStore.openRecordStore(rec_store,true);
        } catch (RecordStoreException ex) {
            ex.printStackTrace();
        }
    }

    private void writeTestData() {
        String[] golfClubs = {"wedge..good form the sand trap","One Wood...of the tee","putter...only","five Iron ... middle"};
        writeRecords(golfClubs);
    }

    private void closeRecStrore() {
        try {
            rs.closeRecordStore();
        } catch (RecordStoreNotOpenException ex) {
            ex.printStackTrace();
        } catch (RecordStoreException ex) {
            ex.printStackTrace();
        }
    }

    private void writeRecords(String[] golfClubs) {
        byte[] record;
        try {
            for (int i = 0; i < golfClubs.length; i++) {
                record = golfClubs[i].getBytes();
                rs.addRecord(record,0,record.length);
            }
        } catch (RecordStoreNotOpenException ex) {
            ex.printStackTrace();
        } catch (RecordStoreException ex) {
            ex.printStackTrace();
        }
    }

    private void searchRecordStore() {
        try {
            if(rs.getNumRecords()>0)
            {
                SearchFilter search = new SearchFilter(tfFind.getString());
                RecordEnumeration re = rs.enumerateRecords(search,null,false);
                if(re.numRecords()>0)
                    siMatch.setText(new String(re.nextRecord()));
                re.destroy();
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }

    public SimpleSearch() {
        display = Display.getDisplay(this);
        exit  = new Command("离开",Command.EXIT,0);
        find = new Command("查找",Command.SCREEN,0);
        tfFind = new TextField("查找","",10,TextField.ANY);
        siMatch = new StringItem(null,null);
        
        fmMain = new Form("记录查询");
        fmMain.addCommand(exit);
        fmMain.addCommand(find);
        
        fmMain.append(tfFind);
        fmMain.append(siMatch);
        fmMain.setCommandListener(this);
        openRecStore();
        writeTestData();
    }
}