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[英]How to store the Value of Object type of a KStream in a Hashmap?
[英]How to store String type of array values in to HashMap object
當我嘗試將String數組值存儲到hashmap時,它將顯示null value.please提供任何解決方案。謝謝提前
String temp;
String[] line=new String[15];
Map<String, String> map=new HashMap<String, String>();
InputStream stream=new FileInputStream(path);
BufferedReader reader =new BufferedReader(new InputStreamReader(stream));
while((temp = reader.readLine()) != null)
{
for(int j=0; j<line.length ;j++)
{
line[j]=reader.readLine();
String fname=line[0];
String lname=line[1];
String mobile=line[2];
String gender=line[3];
//Store array string to map
map.put("fname",fname);
//retrive map object
System.out.println(map.get(fname));
System.out.println(fname);//showing null value in console
System.out.println(lname);//array shows values
System.out.println(mobile);//array shows values
}
您試圖按值獲取地圖值(變量fname)
System.out.println("map.get(fname) = "+map.get(fname));
但你應該使用map.get(key)
,你的密鑰是“fname”(作為字符串)而不是fname(作為變量)
解決方案是
System.out.println("map.get(fname) = "+map.get("fname"));
並且對於FileInputStream嘗試使用file而不是path:
File file = new File("C:/*****");
InputStream stream=new FileInputStream(file);
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