在我的例子中,for() 循环有什么问题?
What's wrong with the for() loop in my case?
我是 Java 和 HBase 的初学者,我想缩短我的代码,所以我在我的代码中使用了 for 循环。如果输入String stumber是"AAAA0000?0",结果应该是"AAAA000000","AAAA000010","AAAA000020","AAAA000030" …… "AAAA000090"
这个源代码运行良好:
List<Get> gets = new ArrayList<>();
for (String stumber : stumbersArr) {
if(stumber.charAt(8) == '?'){
get = new Get((stumber.replace(stumber.charAt(8), '0')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '1')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '2')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '3')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '4')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '5')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '6')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '7')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '8')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '9')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
}else{
get = new Get(stumber.trim().getBytes());
get.setMaxVersions(versions);
gets.add(get);
}
}
Result[] results = table.get(gets);
但是我用for-loop修改后,代码没有给出结果。为什么?
List<Get> gets = new ArrayList<>();
for (String stumber : stumbersArr) {
if(stumber.charAt(8) == '?'){
for (int i =0; i<10; i++){
get = new Get((stumber.replace(stumber.charAt(8), 'i')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
}
}else{
get = new Get(stumber.trim().getBytes());
get.setMaxVersions(versions);
gets.add(get);
}
}
Result[] results = table.get(gets);
for 循环内部应该是:
get = new Get((stumber.replace(stumber.charAt(8), (char)(i + '0'))).getBytes());
什么给你 i
价值作为 char
。
您可以使用 Character.forDigit() 将 int i 转换为 char,例如:
get = new Get((stumber.replace(stumber.charAt(8), Character.forDigit(i, 10))).getBytes());
我是 Java 和 HBase 的初学者,我想缩短我的代码,所以我在我的代码中使用了 for 循环。如果输入String stumber是"AAAA0000?0",结果应该是"AAAA000000","AAAA000010","AAAA000020","AAAA000030" …… "AAAA000090"
这个源代码运行良好:
List<Get> gets = new ArrayList<>();
for (String stumber : stumbersArr) {
if(stumber.charAt(8) == '?'){
get = new Get((stumber.replace(stumber.charAt(8), '0')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '1')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '2')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '3')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '4')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '5')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '6')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '7')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '8')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
get = new Get((stumber.replace(stumber.charAt(8), '9')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
}else{
get = new Get(stumber.trim().getBytes());
get.setMaxVersions(versions);
gets.add(get);
}
}
Result[] results = table.get(gets);
但是我用for-loop修改后,代码没有给出结果。为什么?
List<Get> gets = new ArrayList<>();
for (String stumber : stumbersArr) {
if(stumber.charAt(8) == '?'){
for (int i =0; i<10; i++){
get = new Get((stumber.replace(stumber.charAt(8), 'i')).getBytes());
get.setMaxVersions(versions);
gets.add(get);
}
}else{
get = new Get(stumber.trim().getBytes());
get.setMaxVersions(versions);
gets.add(get);
}
}
Result[] results = table.get(gets);
for 循环内部应该是:
get = new Get((stumber.replace(stumber.charAt(8), (char)(i + '0'))).getBytes());
什么给你 i
价值作为 char
。
您可以使用 Character.forDigit() 将 int i 转换为 char,例如:
get = new Get((stumber.replace(stumber.charAt(8), Character.forDigit(i, 10))).getBytes());