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src/java.base/share/classes/java/lang/ProcessBuilder.java
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*** 23,36 ****
--- 23,39 ----
* questions.
*/
package java.lang;
+ import sun.nio.ch.SelChImpl;
+
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
+ import java.nio.channels.Pipe;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
*** 457,476 ****
--- 460,507 ----
* {@link Type Type}.
*
* @since 1.7
*/
public static abstract class Redirect {
+
+ private static final boolean PIPE_CHANNEL_SUPPORTED;
+
+ static {
+ boolean supported = false;
+ try {
+ Pipe p = Pipe.open();
+ supported = (p.sink() instanceof SelChImpl) &&
+ (p.source() instanceof SelChImpl);
+ try { p.sink().close(); } catch (IOException e) {}
+ try { p.source().close(); } catch (IOException e) {}
+ } catch (IOException e) {
+ // ignore
+ }
+ PIPE_CHANNEL_SUPPORTED = supported;
+ }
+
+ final void checkSupported() throws UnsupportedOperationException {
+ if (this == PIPE_CHANNEL && !PIPE_CHANNEL_SUPPORTED) {
+ throw new UnsupportedOperationException("Unsupported SelectorProvider");
+ }
+ }
+
/**
* The type of a {@link Redirect}.
*/
public enum Type {
/**
* The type of {@link Redirect#PIPE Redirect.PIPE}.
*/
PIPE,
/**
+ * The type of {@link Redirect#PIPE_CHANNEL Redirect.PIPE_CHANNEL}.
+ */
+ PIPE_CHANNEL,
+
+ /**
* The type of {@link Redirect#INHERIT Redirect.INHERIT}.
*/
INHERIT,
/**
*** 513,522 ****
--- 544,571 ----
public static final Redirect PIPE = new Redirect() {
public Type type() { return Type.PIPE; }
public String toString() { return type().toString(); }};
/**
+ * Indicates that subprocess I/O will be connected to the
+ * current Java process over a pipe and that the communication
+ * will be performed via {@link java.nio.channels.Pipe.SourceChannel}
+ * or {@link java.nio.channels.Pipe.SinkChannel}.
+ **
+ * <p>It will always be true that
+ * <pre> {@code
+ * Redirect.PIPE_CHANNEL.file() == null &&
+ * Redirect.PIPE_CHANNEL.type() == Redirect.Type.PIPE_CHANNEL
+ * }</pre>
+ *
+ * @since 1.9
+ */
+ public static final Redirect PIPE_CHANNEL = new Redirect() {
+ public Type type() { return Type.PIPE_CHANNEL; }
+ public String toString() { return type().toString(); }};
+
+ /**
* Indicates that subprocess I/O source or destination will be the
* same as those of the current process. This is the normal
* behavior of most operating system command interpreters (shells).
*
* <p>It will always be true that
*** 685,708 ****
--- 734,770 ----
* returned by {@link Process#getOutputStream()}.
* If the source is set to any other value, then
* {@link Process#getOutputStream()} will return a
* <a href="#redirect-input">null output stream</a>.
*
+ * <p>If the source is {@link Redirect#PIPE_CHANNEL Redirect.PIPE_CHANNEL},
+ * then the standard input of a subprocess can be written to
+ * using the output channel returned by
+ * {@link Process#getOutputChannel()} which, unlike the output stream
+ * above, must be obtained and closed by the user.
+ * If the source is set to any other value, then
+ * {@link Process#getOutputChannel()} will return {@code null}.
+ *
* @param source the new standard input source
* @return this process builder
* @throws IllegalArgumentException
* if the redirect does not correspond to a valid source
* of data, that is, has type
* {@link Redirect.Type#WRITE WRITE} or
* {@link Redirect.Type#APPEND APPEND}
+ * @throws UnsupportedOperationException if the redirect has type
+ * {@link Redirect.Type#PIPE_CHANNEL PIPE_CHANNEL} and the
+ * platform is configured with unsupported
+ * {@link java.nio.channels.spi.SelectorProvider}
* @since 1.7
*/
public ProcessBuilder redirectInput(Redirect source) {
if (source.type() == Redirect.Type.WRITE ||
source.type() == Redirect.Type.APPEND)
throw new IllegalArgumentException(
"Redirect invalid for reading: " + source);
+ source.checkSupported();
redirects()[0] = source;
return this;
}
/**
*** 717,738 ****
--- 779,812 ----
* Process#getInputStream()}.
* If the destination is set to any other value, then
* {@link Process#getInputStream()} will return a
* <a href="#redirect-output">null input stream</a>.
*
+ * <p>If the destination is {@link Redirect#PIPE_CHANNEL Redirect.PIPE_CHANNEL},
+ * then the standard output of a subprocess can be read using the input
+ * channel returned by {@link Process#getInputChannel()}. which,
+ * unlike the input stream above, must be obtained and closed by the user.
+ * If the destination is set to any other value, then
+ * {@link Process#getInputChannel()} will return {@code null}.
+ *
* @param destination the new standard output destination
* @return this process builder
* @throws IllegalArgumentException
* if the redirect does not correspond to a valid
* destination of data, that is, has type
* {@link Redirect.Type#READ READ}
+ * @throws UnsupportedOperationException if the redirect has type
+ * {@link Redirect.Type#PIPE_CHANNEL PIPE_CHANNEL} and the
+ * platform is configured with unsupported
+ * {@link java.nio.channels.spi.SelectorProvider}
* @since 1.7
*/
public ProcessBuilder redirectOutput(Redirect destination) {
if (destination.type() == Redirect.Type.READ)
throw new IllegalArgumentException(
"Redirect invalid for writing: " + destination);
+ destination.checkSupported();
redirects()[1] = destination;
return this;
}
/**
*** 757,772 ****
--- 831,851 ----
* @return this process builder
* @throws IllegalArgumentException
* if the redirect does not correspond to a valid
* destination of data, that is, has type
* {@link Redirect.Type#READ READ}
+ * @throws UnsupportedOperationException if the redirect has type
+ * {@link Redirect.Type#PIPE_CHANNEL PIPE_CHANNEL} and the
+ * platform is configured with unsupported
+ * {@link java.nio.channels.spi.SelectorProvider}
* @since 1.7
*/
public ProcessBuilder redirectError(Redirect destination) {
if (destination.type() == Redirect.Type.READ)
throw new IllegalArgumentException(
"Redirect invalid for writing: " + destination);
+ destination.checkSupported();
redirects()[2] = destination;
return this;
}
/**
*** 895,905 ****
*
* <p>If this property is {@code true}, then any error output
* generated by subprocesses subsequently started by this object's
* {@link #start()} method will be merged with the standard
* output, so that both can be read using the
! * {@link Process#getInputStream()} method. This makes it easier
* to correlate error messages with the corresponding output.
* The initial value is {@code false}.
*
* @return this process builder's {@code redirectErrorStream} property
*/
--- 974,985 ----
*
* <p>If this property is {@code true}, then any error output
* generated by subprocesses subsequently started by this object's
* {@link #start()} method will be merged with the standard
* output, so that both can be read using the
! * {@link Process#getInputStream()} or {@link Process#getInputChannel()}
! * methods. This makes it easier
* to correlate error messages with the corresponding output.
* The initial value is {@code false}.
*
* @return this process builder's {@code redirectErrorStream} property
*/
*** 912,922 ****
*
* <p>If this property is {@code true}, then any error output
* generated by subprocesses subsequently started by this object's
* {@link #start()} method will be merged with the standard
* output, so that both can be read using the
! * {@link Process#getInputStream()} method. This makes it easier
* to correlate error messages with the corresponding output.
* The initial value is {@code false}.
*
* @param redirectErrorStream the new property value
* @return this process builder
--- 992,1003 ----
*
* <p>If this property is {@code true}, then any error output
* generated by subprocesses subsequently started by this object's
* {@link #start()} method will be merged with the standard
* output, so that both can be read using the
! * {@link Process#getInputStream()} or {@link Process#getInputChannel()}
! * methods. This makes it easier
* to correlate error messages with the corresponding output.
* The initial value is {@code false}.
*
* @param redirectErrorStream the new property value
* @return this process builder
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