如何使用java在文本文件的两行之间获取文本

Question

如何使用Java在文本文件的两行之间获取文本？ 我尝试这样做，但它不起作用：

Attempt to invoke virtual method 'android.support.v7.app.AlertDialog android.support.v7.app.AlertDialog$Builder.create()' on a null object reference

Answer 1

更新回答

使用正则表达式

String pattern = "([\\s\\S]*?)(!!!Error deploying file)";

上述模式的解释。

1. *？ - 匹配零和无限次之间的单个字符
2. \ s - 匹配任何空格字符
3. \ S - 匹配任何非空白字符

示例代码：

String line = "!!!Error deploying file order\\POST_ORDER_UpdateTaxAmountCurrInCo.sql at 22-JUL-16 08:07:Chathura aBhanakana1!!!Error deploying file order\\POST_ORDER_UpdateTaxAmountChathura aBhanakana1AAAAA !!!Error deploying file order\\POST";

String pattern = "([\\s\\S]*?)(!!!Error deploying file)";

// Create a Pattern object
Pattern r = Pattern.compile(pattern);

// Now create matcher object.
Matcher m = r.matcher(line);
while (m.find( )) {
  String str = m.group(1);
  if(str != null && !str.isEmpty()){
     System.out.println("Found value: " + str );
   }
} 

输出

1. 找到值：订单\ POST_ORDER_UpdateTaxAmountCurrInCo.sql at 22-JUL-16 08:07：Chathura aBhanakana1
2. 发现价值： 订单\ POST_ORDER_UpdateTaxAmountChathura aBhanakana1AAAAA

Check output here

使用拆分方法

示例代码：

String line = "!!!Error deploying file order\\POST_ORDER_UpdateTaxAmountCurrInCo.sql at 22-JUL-16 08:07:Chathura aBhanakana1!!!Error deploying file order\\POST_ORDER_UpdateTaxAmountChathura aBhanakana1AAAAA !!!Error deploying file order\\POST";

for (String retval: line.split("!!!Error deploying file")){
       System.out.println(retval);
 }

输出：

1 ) order\POST_ORDER_UpdateTaxAmountCurrInCo.sql at 22-JUL-16 08:07:Chathura aBhanakana1
2) order\POST_ORDER_UpdateTaxAmountChathura aBhanakana1AAAAA
3) order\POST

Check output here