java字符串去重寫文件學習筆記
阿新 • • 發佈:2018-11-16
app 使用 一行 寫文件 ont 字符數 code ava buffer
/**
* * 使用Scanner從鍵盤讀取一行輸入,去掉其中重復字符, 打印出不同的那些字符
* aaaabbbcccddd
*
* 分析:
* 1,創建Scanner對象
* 2,創建HashSet對象,將字符存儲,去掉重復
* 3,將字符串轉換為字符數組,獲取每一個字符存儲在HashSet集合中,自動去除重復
* 4,遍歷HashSet,打印每一個字符
*/
@Test
public void jihe9() {
String ss = "aaaabbbcccdddwerwrweddcsecsefwewe";
HashSet<Character> hs = new HashSet<>();
char[] chars = ss.toCharArray();
for (char c : chars) {
hs.add(c);
}
System.out.println(hs);
StringBuilder stringBuilder = new StringBuilder();
for (Character s : hs) {
stringBuilder.append(s.toString());
}
System.out.println(stringBuilder);
System.out.println("88888888888888888888888888888");
HashMap<Character, Integer> map = new HashMap<>();
for (char c : chars) {
map.put(c, !map.containsKey(c) ? 1 : map.get(c) + 1);
}
for (Character c : map.keySet()) {
System.out.println(c+"="+map.get(c));
}
try {
BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter("x.txt"));
for (Map.Entry<Character, Integer> m : map.entrySet()) {
bufferedWriter.write(m.getKey() + ":" + m.getValue()+",");
}
System.out.println("寫入成功!!");
bufferedWriter.close();
} catch (IOException e) {
e.printStackTrace();
}
}
java字符串去重寫文件學習筆記