J2ME中RMS的使用解析

package com.cuilichen.usual; 
import java.io.ByteArrayInputStream;//要使用到的各种输入输出流 

import java.io.ByteArrayOutputStream; 

import java.io.DataInputStream; 

import java.io.DataOutputStream; 
public class Appointment {//单一记录的类名 

private int int1; // 

private int int2; // 

private long long1; 

private String str1; //str1作为保留字段，记录检索的关键字 

private String str2; // 

private String str3; // 

private boolean WroteFlag; // 
public Appointment() { 

} 
public Appointment(int _int1, int _int2, long _long1, String _str1, 

String _str2, String _str3, boolean _WroteFlag) { 

this.int1 = _int1; //写入RMS的构造函数 

this.int2 = _int2; 

this.long1 = _long1; 

this.str1 = _str1; 

this.str2 = _str2; 

this.str3 = _str3; 

this.WroteFlag = _WroteFlag; 

} 
public Appointment(byte[] rec) { 

initAppointmnet(rec); //读取RMS内容的构造函数 

} 
public byte[] toBytes() { //写成字节 
byte[] data = null; 
try { 

ByteArrayOutputStream baos = new ByteArrayOutputStream(); 

DataOutputStream dos = new DataOutputStream(baos); 

dos.writeInt(int1); 

dos.writeInt(int2); 

dos.writeLong(long1); 

dos.writeUTF(str1); 

dos.writeUTF(str2); 

dos.writeUTF(str3); 

dos.writeBoolean(WroteFlag); 

data = baos.toByteArray(); 

baos.close(); 

dos.close(); 

} catch (Exception e) { 

e.printStackTrace(); 

} 

return data; 

} 
public void initAppointmnet(byte[] rec) { //从字节读取内容 
ByteArrayInputStream bais = new ByteArrayInputStream(rec); 

DataInputStream dis = new DataInputStream(bais); 
try { 

int1 = dis.readInt(); 

int2 = dis.readInt(); 

long1 = dis.readLong(); 

str1 = dis.readUTF(); 

str2 = dis.readUTF(); 

str3 = dis.readUTF(); 

WroteFlag = dis.readBoolean(); 

} catch (Exception e) { 

e.printStackTrace(); 

} 

} 

public int getInt1() { //int 

return int1; 

}

public int getInt2() { 

return int2; 

}

public long getLong1() { 

return long1; 

} 
public String getStr1() { //String 

return str1; 

} 
public String getStr2() { //String 

return str2; 

} 
public String getStr3() { 

return str3; 

} 
public boolean getWroteFlag() { //返回写入标志 

return WroteFlag; 

} 

} 

package com.cuilichen.usual; 
import javax.microedition.rms.RecordEnumeration; 

import javax.microedition.rms.RecordStore; 
public class RMS { 

public static final int Int1 = 0;//各个字段的默认数值 

public static final int Int2 = 0; 

public static final long Long1 = 0; 

public static final String Str1 = ""; 

public static final String Str2 = ""; 

public static final String Str3 = ""; 
public static boolean addRecord(String name, int int1, int int2,//添加记录 

long long1, String str1, String str2, String str3, boolean b) { 

boolean success = false; 
try { 

RecordStore rs = RecordStore.openRecordStore(name, true); 

Appointment app = new Appointment(int1, int2, long1, str1, str2,str3, b); 

//既然str1作为保留字段，我们在这里就要如此操作：例如int1为我们设定的关键字，那么str1 = Integer.toString(int1); 

byte[] data = app.toBytes(); 

rs.addRecord(data, 0, data.length); 

rs.closeRecordStore(); 

success = true; 

} catch (Exception e) { 

e.printStackTrace(); 

}

return success; 

}

public static int getNumOfRecords(String name) {//得到RMS中记录的条数 

try { 

RecordStore rs = RecordStore.openRecordStore(name, true); 
return rs.getNumRecords(); 

} catch (Exception e) { 

return 0; 

} 

} 
public static Appointment[] getRecords(String name) {//取得RMS中的所有记录 

Appointment[] result = { }; 
try { 

RecordStore rs = RecordStore.openRecordStore(name, false); 

RecordEnumeration re = rs.enumerateRecords(null, null, false); 

result = new Appointment[rs.getNumRecords()]; 
for (int i = 0; i < result.length; i++) { 

int j = re.previousRecordId(); 

Appointment app = new Appointment(rs.getRecord(j)); 

result = app; 
//System.out.println("app["+i+"] "+app.getStr2()); 

} 
rs.closeRecordStore(); 

} catch (Exception e) { 

} 
return result; 

} 

public static Appointment getRecord(String name, int j) {//根据记录编号（参数 int j）取得一条记录 

Appointment result = new Appointment(); 
try { 

RecordStore rs = RecordStore.openRecordStore(name, false); 

RecordEnumeration re = rs.enumerateRecords(null, null, false); 

result = new Appointment(rs.getRecord(j)); 

rs.closeRecordStore(); 

} catch (Exception e) { 

} 
return result; 

} 
public static int getIndex(String name, String content) {//得到记录号int j，这里需要使用保留字段str1 

RecordStore rs = null; 

RecordEnumeration re = null; 
try { 

rs = RecordStore.openRecordStore(name, false); //open 

re = rs.enumerateRecords(null, null, false); //enumeration 
for (int i = 0; i < RMS.getNumOfRecords(name); i++) { 

int j = re.nextRecordId(); 

Appointment app = new Appointment(rs.getRecord(j)); 
if (app.getStr1().equals(content)) { 

return j; 

} 

} 

} catch (Exception e) { 

}

return 1; 

} 
public static boolean setRecord(String name, int id, int int1, int int2,//设置记录号为id的记录 

long long1, String str1, String str2, String str3, boolean b) { 

boolean success = false; 

RecordStore rs = null; 

RecordEnumeration re = null; 
try { 

rs = RecordStore.openRecordStore(name, false); //open 

re = rs.enumerateRecords(null, null, false); //enumeration 
Appointment app = new Appointment(int1, int2, long1, str1, str2, str3, b); 

//str1作为保留字段，在这里如此操作：例如若int1为我们设定的关键字，那么str1 = Integer.toString(int1); 
byte[] data = app.toBytes(); 

rs.setRecord(id, data, 0, data.length); 

success = true; 

rs.closeRecordStore(); 

} catch (Exception e) { 

} 
return success; 

} 

} 

protected void startApp() throws MIDletStateChangeException { 

if (RMS.getNumOfRecords(rsName) = = 0) {//rsName在前面已经声明了。String rsName＝“MyRMS”； 

for (int i = 0; i <6; i++) { 

RMS.addRecord(rsName, RMS.Int1, i, RMS.Long1, Integer . toString(i), RMS.Str2, "1234567890123456789",false); 

} 

}它就在RMS中增加了6条记录，其中int1，long1，str2，WroteFlag都没有使用，我们只是使用int2，str1（作为保留字段）和str3。 

}