返回的值错误,但在系统中读取结果良好?JAVA
我正在尝试读取此输入:返回的值错误,但在系统中读取结果良好?JAVA,java,Java,我正在尝试读取此输入: processcount 2 # Read 2 processes runfor 15 # Run for 15 time units use rr # Can be fcfs, sjf, or rr quantum 2 # Time quantum – only if using rr process name P1 arrival 3 burst 5 process name P2 arrival 0
processcount 2 # Read 2 processes
runfor 15 # Run for 15 time units
use rr # Can be fcfs, sjf, or rr
quantum 2 # Time quantum – only if using rr
process name P1 arrival 3 burst 5
process name P2 arrival 0 burst 9
end
我的工作是只解析值而不是单词,并保留注释(#)
以下是主文件:
public class main {
static String[] token = new String[10];
static List<Schedule> p;
public static void schedule()
{
for(Schedule c: p)
{
System.out.println("ProcessInfo: " + c.getProcess().processName);
System.out.println("count: " + c.getProcessCount());
System.out.println("quant: " + c.getQuantum());
System.out.println("runtime: " + c.getRunTime());
System.out.println("Type: " + c.getType());
}
}
public static void main(String[] args) throws Exception {
Scanner sc = new Scanner(System.in);
// sc = new Scanner(new File("processes.in"));
p = new ArrayList<>();
while(sc.hasNextLine() && !sc.equals("end"))
{
token = sc.nextLine().replace(" ","-").replace("#", "-").split("-");
System.out.println(token[0].toString());
if(!token[0].startsWith("#") || !sc.nextLine().startsWith("end"))
{
Schedule s = new Schedule();
int pCount=0, runfor=0, quantum=0, arrival=0, burst=0;
String type = null, pName = null;
if(token[0].startsWith("processcount"))
{
s.setProcessCount(Integer.parseInt(token[1]));
System.out.println(Integer.parseInt(token[1] +""));
}
else if(token[0].startsWith("runfor"))
{
s.setRunTime(Integer.valueOf(token[1].toString()));
System.out.println(Integer.parseInt(token[1]) +"");
}
else if(token[0].startsWith("use"))
{
s.setType(token[1].toString());
System.out.println(token[1] +"");
}
else if(token[0].startsWith("quantum"))
{
s.setQuantum(Integer.valueOf(token[1].toString()));
System.out.println(token[1] + "");
}
else if(token[0].startsWith("process"))
{
Processes pl = new Processes();
pl.setProcessName(token[2]);
System.out.println(token[2]+ "");
pl.setArrivalTime(Integer.valueOf(token[4].toString()));
System.out.println(""+ Integer.valueOf(token[4]));
pl.setBurstTime(Integer.valueOf(token[6].toString()));
System.out.println("" + token[6]);
s.setProcess(pl);
// add info
p.add(s);
}
else if(token[0].startsWith("end"))
{
schedule();
}
}
}
}
}
过程如下:
public class Processes {
String processName;
int arrivalTime;
int burstTime;
public String getProcessName() {
return processName;
}
public void setProcessName(String processName) {
this.processName = processName;
}
public int getArrivalTime() {
return arrivalTime;
}
public void setArrivalTime(int arrivalTime) {
this.arrivalTime = arrivalTime;
}
public int getBurstTime() {
return burstTime;
}
public void setBurstTime(int burstTime) {
this.burstTime = burstTime;
}
}
以下是我的代码得到的输出:
ProcessInfo: P1
count: 0
quant: 0
runtime: 0
Type: null
ProcessInfo: P2
count: 0
quant: 0
runtime: 0
Type: null
为什么返回了错误的结果?由于拆分字符串的方式,您遇到了问题。现在的方式首先用破折号替换每个空格。例如,字符串
"processcount 2 # a comment"
将成为
"processcount-2---#-a-comment"
然后将其拆分,在每对破折号之间提供一个空字符串,这样您将得到
token = ["processcount", "2", "","", ... etc]
我建议你这样做:
String str = (sc.nextLine().split("#"))[0]; //get the string before the pound sign
str = str.trim(); //remove the leading/trailing whitespace
token = str.split("\\s+"); //split the string by the whitespaces
您遇到问题是因为您拆分字符串的方式。现在的方式首先用破折号替换每个空格。例如,字符串
"processcount 2 # a comment"
将成为
"processcount-2---#-a-comment"
然后将其拆分,在每对破折号之间提供一个空字符串,这样您将得到
token = ["processcount", "2", "","", ... etc]
我建议你这样做:
String str = (sc.nextLine().split("#"))[0]; //get the string before the pound sign
str = str.trim(); //remove the leading/trailing whitespace
token = str.split("\\s+"); //split the string by the whitespaces
这里有两个问题。在while循环的每个迭代中创建一个新的计划;在新的迭代之前,您没有获得当前行的所有相关值,而且在创建一个覆盖以前收集的值的新Schedule()之后,您有两个无用的变量。 此外,在数组的字符串元素上使用toString,这是没有意义的。我不会尝试不使用过滤器,你也不需要任何过滤器。总是尝试(保持简单愚蠢) 下面是我将如何在不使用过滤器的情况下进行操作
public static void main (String args [])
{
// Will help us identify the key words
String current_token;
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();
//Remove spaces at the beginning and end of the string
input = input.trim();
Schedule s = new Schedule();
// New source for the scanner
sc =new Scanner(input);
p = new ArrayList<>();
while(sc.hasNext())
{
current_token = sc.next();
if(current_token.equals("end"))
{schedule(); break;}
switch(current_token)
{
case "processcount":
s.setProcessCount(sc.nextInt());
System.out.println(s.getProcessCount()+ " ");
break;
case "runfor":
s.setRunTime(sc.nextInt());
System.out.println(s.getRuntime +" ");
case "use":
s.setType(sc.next());
System.out.println(s.getType() +" ");
break;
case "quantum":
s.setQuantum(sc.nextInt());
System.out.println(s.getQuantum + " ");
break;
case "process":
Processes pl = new Processes();
pl.setProcessName(sc.next());
System.out.println(pl.GetProcessName()+ " ");
pl.setArrivalTime(sc.nextInt());
System.out.println(" "+ pl.getArrivalTime());
pl.setBurstTime(sc.nextInt());
System.out.println(" " + pl.getBurstTime());
s.setProcess(pl);
// add info
p.add(s);
break;
default:
// the current_token is not what we are looking for
break;
}
}
}
publicstaticvoidmain(字符串参数[])
{
//将帮助我们识别关键词
字符串当前_令牌;
扫描仪sc=新的扫描仪(System.in);
字符串输入=sc.nextLine();
//删除字符串开头和结尾的空格
input=input.trim();
附表s=新附表();
//扫描仪的新来源
sc=新扫描仪(输入);
p=新的ArrayList();
while(sc.hasNext())
{
当前_令牌=sc.next();
if(当前符号等于(“结束”))
{schedule();break;}
交换机(当前令牌)
{
案例“processcount”:
s、 setProcessCount(sc.nextInt());
System.out.println(s.getProcessCount()+“”);
打破
案例“runfor”:
s、 setRunTime(sc.nextInt());
System.out.println(s.getRuntime+“”);
案例“使用”:
s、 setType(sc.next());
System.out.println(s.getType()+);
打破
案例“quantum”:
s、 setQuantum(sc.nextInt());
System.out.println(s.getQuantum+“”);
打破
案例“过程”:
流程pl=新流程();
pl.setProcessName(sc.next());
System.out.println(pl.GetProcessName()+);
pl.setArrivalTime(sc.nextInt());
System.out.println(“+pl.getArrivalTime());
pl.setBurstTime(sc.nextInt());
System.out.println(“+pl.getBurstTime());
s、 setProcess(pl);
//添加信息
p、 添加(s);
打破
违约:
//当前的_令牌不是我们正在寻找的
打破
}
}
}
这里有几个问题。在while循环的每个迭代中创建一个新的计划;在新的迭代之前,您没有获得当前行的所有相关值,而且在创建一个覆盖以前收集的值的新Schedule()之后,您有两个无用的变量。
此外,在数组的字符串元素上使用toString,这是没有意义的。我不会尝试不使用过滤器,你也不需要任何过滤器。总是尝试(保持简单愚蠢)
下面是我将如何在不使用过滤器的情况下进行操作
public static void main (String args [])
{
// Will help us identify the key words
String current_token;
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();
//Remove spaces at the beginning and end of the string
input = input.trim();
Schedule s = new Schedule();
// New source for the scanner
sc =new Scanner(input);
p = new ArrayList<>();
while(sc.hasNext())
{
current_token = sc.next();
if(current_token.equals("end"))
{schedule(); break;}
switch(current_token)
{
case "processcount":
s.setProcessCount(sc.nextInt());
System.out.println(s.getProcessCount()+ " ");
break;
case "runfor":
s.setRunTime(sc.nextInt());
System.out.println(s.getRuntime +" ");
case "use":
s.setType(sc.next());
System.out.println(s.getType() +" ");
break;
case "quantum":
s.setQuantum(sc.nextInt());
System.out.println(s.getQuantum + " ");
break;
case "process":
Processes pl = new Processes();
pl.setProcessName(sc.next());
System.out.println(pl.GetProcessName()+ " ");
pl.setArrivalTime(sc.nextInt());
System.out.println(" "+ pl.getArrivalTime());
pl.setBurstTime(sc.nextInt());
System.out.println(" " + pl.getBurstTime());
s.setProcess(pl);
// add info
p.add(s);
break;
default:
// the current_token is not what we are looking for
break;
}
}
}
publicstaticvoidmain(字符串参数[])
{
//将帮助我们识别关键词
字符串当前_令牌;
扫描仪sc=新的扫描仪(System.in);
字符串输入=sc.nextLine();
//删除字符串开头和结尾的空格
input=input.trim();
附表s=新附表();
//扫描仪的新来源
sc=新扫描仪(输入);
p=新的ArrayList();
while(sc.hasNext())
{
当前_令牌=sc.next();
if(当前符号等于(“结束”))
{schedule();break;}
交换机(当前令牌)
{
案例“processcount”:
s、 setProcessCount(sc.nextInt());
System.out.println(s.getProcessCount()+“”);
打破
案例“runfor”:
s、 setRunTime(sc.nextInt());
System.out.println(s.getRuntime+“”);
案例“使用”:
s、 setType(sc.next());
System.out.println(s.getType()+);
打破
案例“quantum”:
s、 setQuantum(sc.nextInt());
System.out.println(s.getQuantum+“”);
打破
案例“过程”:
流程pl=新流程();
pl.setProcessName(sc.next());
System.out.println(pl.GetProcessName()+);
pl.setArrivalTime(sc.nextInt());
System.out.println(“+pl.getArrivalTime());
pl.setBurstTime(sc.nextInt());
System.out.println(“+pl.getBurstTime());
s、 setProcess(pl);
//添加信息
p、 添加(s);
打破
违约:
//当前的_令牌不是我们想要的