检查文本区域的内容是否为空（java）
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Check if the content of text area is empty (java)
提问by user1748910
I am trying to read data from a textarea (JTextArea)and store the contents into a table(MySQL). I don't want the INSERTquery to execute if the textarea is empty or has a newline without any text. I tried the following code but it does not work. Could someone help me out. Thanks.
我正在尝试从 a 读取数据textarea (JTextArea)并将内容存储到table(MySQL). INSERT如果 textarea 为空或有一个没有任何文本的换行符，我不希望执行查询。我尝试了以下代码，但它不起作用。有人可以帮我吗。谢谢。
String data=todo_area.getText();//read contents of text area into 'data'
String newline = System.getProperty("line.separator");
boolean hasNewline = data.contains(newline);
if (data == null || !data.trim().equals("")||hasNewline==false)
{
//INSERT query
}
回答by Rasel
String data=todo_area.getText().trim(); //read contents of text area into 'data'
if(!data.equals("")) {
// code
}
回答by user1835172
For me it's enough using this condition:
对我来说，使用这个条件就足够了：
if ((data.trim().length() > 0) && (!hasNewline)){
//do the insert
}
data.trim().length() > 0is enough to make sure that the input is not null.
data.trim().length() > 0足以确保输入不为空。
回答by Abubakkar
Try using this condition for you check:
尝试使用此条件进行检查：
if ((data != null) && (data.trim().length() > 0 ) && (!hasNewline)){
//do the insert
}
