save.java

j2me小游戏,入门级的学习很好:)

import javax.microedition.rms.*;

public class Save {
	
	public static RecordStore open(String rsname) {
		RecordStore rs = null;
		if(rsname.length() > 32)
			return null;
		try {
			rs = RecordStore.openRecordStore(rsname,true);
			return rs;
		}catch(Exception e){
			return null;
		}
	}

	public static int writeChar2RS(RecordStore rs,char data) {
		byte[]temp = new byte[2];
		temp[0] = (byte)(0xff&(data >> 8));
		temp[1] = (byte)(0xff&(data >> 0));
		try {
			return rs.addRecord(temp,0,temp.length);
		}catch(Exception e){
		}
		return -1;
	}
	
	public static int writeInt2RS(RecordStore rs,int data) {
		byte[]temp = new byte[4];
		temp[0] = (byte)(0xff&(data >> 24));
		temp[1] = (byte)(0xff&(data >> 16));
		temp[2] = (byte)(0xff&(data >> 8));
		temp[3] = (byte)(0xff&(data >> 0));
		try {
			return rs.addRecord(temp,0,temp.length);
		}catch(Exception e){
		}
		return -1;
	}
	
	public static char readChar4RS(RecordStore rs,int recordID) {
		byte[]temp = new byte[2];
		try {
			temp = rs.getRecord(recordID);
		}catch(Exception e) {
		}
		char result = (char)(temp[0]&0x00ff);
		result = (char)((result << 8) + (char)(temp[1]&0x00ff));
		return result;
	}
	
	public static int readInt4RS(RecordStore rs,int recordID) {
		byte[]temp = new byte[4];
		try {
			temp = rs.getRecord(recordID);
		}catch(Exception e) {
		}
		int result = (temp[0]&0x00ff);
		result = (result << 8) + (temp[1]&0x00ff);
		result = (result << 8) + (temp[2]&0x00ff);
		result = (result << 8) + (temp[3]&0x00ff);
		return result;
	}
	
	public static int[] travelRS(RecordStore rs) {
		int point = 0,i=0;
		int ladder[] = {0,0,0,0,0};
		byte[] temp;
		try {
			RecordEnumeration re = rs.enumerateRecords(null,null,false);
			while(re.hasNextElement()) {
				temp = re.nextRecord();
				point = (temp[0]&0x00ff);
				point = (point << 8) + (temp[1]&0x00ff);
				point = (point << 8) + (temp[2]&0x00ff);
				point = (point << 8) + (temp[3]&0x00ff);
				if(ladder[0] < point) {
					ladder[4] = ladder[3];
					ladder[3] = ladder[2];
					ladder[2] = ladder[1];
					ladder[1] = ladder[0];
					ladder[0] = point;
				}
				if(ladder[0] < point)
					ladder[0] = point;
				if((ladder[1] < point)&(ladder[0] != point))
					ladder[1] = point;
				if((ladder[2] < point)&(ladder[0] != point)&(ladder[1] != point))
					ladder[2] = point;
				if((ladder[3] < point)&(ladder[0] != point)&(ladder[1] != point)&(ladder[2] != point))
					ladder[3] = point;
				if((ladder[4] < point)&(ladder[0] != point)&(ladder[1] != point)&(ladder[2] != point)&(ladder[3] != point))
					ladder[4] = point;
			}
		}catch(Exception e) {
		}
		return ladder;
	}
	
}