LineIterator (abacus API Documentation)

java.lang.Object
- com.landawn.abacus.util.LineIterator

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable, java.util.Iterator<java.lang.String>
```
public final class LineIterator
extends java.lang.Object
implements java.util.Iterator<java.lang.String>, java.io.Closeable
```
Note: it's copied from Apache Commons IO developed at The Apache Software Foundation (http://www.apache.org/), or under the Apache License 2.0. An Iterator over the lines in a Reader.
LineIterator holds a reference to an open Reader. When you have finished with the iterator you should close the reader to free internal resources. This can be done by closing the reader directly, or by calling the close() or #closeAllQuietly(LineIterator) method on the iterator.
The recommended usage pattern is:
```
 try(LineIterator it = FileUtils.lineIterator(file, "UTF-8")) {
   while (it.hasNext()) {
     String line = it.nextLine();
     // do something with line
   }
 }
 
```
Since:

1.2

Version:

$Id: LineIterator.java 1471767 2013-04-24 23:24:19Z sebb $

Constructor Summary

Constructors
Constructor and Description

LineIterator(java.io.Reader reader)
Constructs an iterator of the lines for a Reader.

Constructors
Constructor and Description
`LineIterator(java.io.Reader reader)` Constructs an iterator of the lines for a `Reader`.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`void`	`close()` Closes the underlying `Reader` quietly.
`boolean`	`hasNext()` Indicates whether the `Reader` has more lines.
`java.lang.String`	`next()` Returns the next line in the wrapped `Reader`.
`static java.util.List<LineIterator>`	`of(java.util.Collection<? extends java.io.Reader> readers)`
`static LineIterator`	`of(java.io.File file)` Returns an Iterator for the lines in a `File` using the default encoding for the VM.
`static LineIterator`	`of(java.io.File file, java.nio.charset.Charset encoding)` Returns an Iterator for the lines in a `File`.
`static LineIterator`	`of(java.io.InputStream input)`
`static LineIterator`	`of(java.io.InputStream input, java.nio.charset.Charset encoding)` Returns an Iterator for the lines in an `InputStream`, using the character encoding specified (or default encoding if null).
`static LineIterator`	`of(java.io.Reader reader)`
`void`	`remove()` Deprecated.

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Iterator
forEachRemaining

- Constructor Detail
  - LineIterator
```
public LineIterator(java.io.Reader reader)
             throws java.lang.IllegalArgumentException
```
    Constructs an iterator of the lines for a Reader.
    
    Parameters:
    
    reader - the Reader to read from, not null
    
    Throws:
    
    java.lang.IllegalArgumentException - if the reader is null
- Method Detail
  - of
```
public static LineIterator of(java.io.File file)
```
    Returns an Iterator for the lines in a File using the default encoding for the VM.
    
    Parameters:
    
    file - the file to open for input, must not be null
    
    Returns:
    
    an Iterator of the lines in the file, never null
    
    Throws:
    
    UncheckedIOException - in case of an I/O error (file closed)
    
    See Also:
    
    #lineIterator(File, Charset)
  - of
```
public static LineIterator of(java.io.File file,
                              java.nio.charset.Charset encoding)
```
    Returns an Iterator for the lines in a File.
    This method opens an InputStream for the file. When you have finished with the iterator you should close the stream to free internal resources. This can be done by calling the close() or IOUtil#closeQuietly(LineIterator) method.
    The recommended usage pattern is:
```
 LineIterator it = FileUtils.lineIterator(file, "UTF-8");
 try {
   while (it.hasNext()) {
     String line = it.nextLine();
     /// do something with line
   }
 } finally {
   closeQuietly(iterator);
 }
 
```
    If an exception occurs during the creation of the iterator, the underlying stream is closed.
    Parameters:
    
    file - the file to open for input, must not be null
    
    encoding - the encoding to use, null means platform default
    
    Returns:
    
    an Iterator of the lines in the file, never null
    
    Throws:
    
    UncheckedIOException - in case of an I/O error (file closed)
  - of
```
public static LineIterator of(java.io.InputStream input)
```
  - of
```
public static LineIterator of(java.io.InputStream input,
                              java.nio.charset.Charset encoding)
```
    Returns an Iterator for the lines in an InputStream, using the character encoding specified (or default encoding if null).
    LineIterator holds a reference to the open InputStream specified here. When you have finished with the iterator you should close the stream to free internal resources. This can be done by closing the stream directly, or by calling close() or IOUtil#closeQuietly(LineIterator).
    The recommended usage pattern is:
```
 try {
   LineIterator it = lineIterator(stream, charset);
   while (it.hasNext()) {
     String line = it.nextLine();
     /// do something with line
   }
 } finally {
   closeQuietly(stream);
 }
 
```
    Parameters:
    
    input - the InputStream to read from, not null
    
    encoding - the encoding to use, null means platform default
    
    Returns:
    
    an Iterator of the lines in the reader, never null
    
    Throws:
    
    java.lang.IllegalArgumentException - if the input is null
    
    UncheckedIOException - if an I/O error occurs, such as if the encoding is invalid
  - of
```
public static LineIterator of(java.io.Reader reader)
```
  - of
```
public static java.util.List<LineIterator> of(java.util.Collection<? extends java.io.Reader> readers)
```
  - hasNext
```
public boolean hasNext()
```
    Indicates whether the Reader has more lines. If there is an IOException then close() will be called on this instance.
    
    Specified by:
    
    hasNext in interface java.util.Iterator<java.lang.String>
    
    Returns:
    
    true if the Reader has more lines
    
    Throws:
    
    java.lang.IllegalStateException - if an IO exception occurs
  - next
```
public java.lang.String next()
```
    Returns the next line in the wrapped Reader.
    
    Specified by:
    
    next in interface java.util.Iterator<java.lang.String>
    
    Returns:
    
    the next line from the input
    
    Throws:
    
    java.util.NoSuchElementException - if there is no line to return
  - close
```
public void close()
```
    Closes the underlying Reader quietly. This method is useful if you only want to process the first few lines of a larger file. If you do not close the iterator then the Reader remains open. This method can safely be called multiple times.
    
    Specified by:
    
    close in interface java.io.Closeable
    
    Specified by:
    
    close in interface java.lang.AutoCloseable
  - remove
```
@Deprecated
public void remove()
```
    Deprecated.
    
    Unsupported.
    
    Specified by:
    
    remove in interface java.util.Iterator<java.lang.String>
    
    Throws:
    
    java.lang.UnsupportedOperationException - always

Class LineIterator

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Iterator

Constructor Detail

LineIterator

Method Detail

of

of

of

of

of

of

hasNext

next

close

remove