@ -17,9 +17,13 @@
package org.springframework.boot ;
import java.io.File ;
import java.io.FileNotFoundException ;
import java.io.FileWriter ;
import java.io.IOException ;
import java.lang.management.ManagementFactory ;
import java.nio.file.Files ;
import java.nio.file.attribute.PosixFilePermission ;
import java.util.Set ;
import org.springframework.util.Assert ;
import org.springframework.util.ObjectUtils ;
@ -31,6 +35,10 @@ import org.springframework.util.ObjectUtils;
* /
public class ApplicationPid {
private static final PosixFilePermission [ ] WRITE_PERMISSIONS = {
PosixFilePermission . OWNER_WRITE , PosixFilePermission . GROUP_WRITE ,
PosixFilePermission . OTHERS_WRITE } ;
private final String pid ;
public ApplicationPid ( ) {
@ -81,6 +89,7 @@ public class ApplicationPid {
public void write ( File file ) throws IOException {
Assert . state ( this . pid ! = null , "No PID available" ) ;
createParentFolder ( file ) ;
assertCanWrite ( file ) ;
try ( FileWriter writer = new FileWriter ( file ) ) {
writer . append ( this . pid ) ;
}
@ -93,4 +102,27 @@ public class ApplicationPid {
}
}
private void assertCanWrite ( File file ) throws IOException {
if ( ! file . canWrite ( ) | | ! canWritePosixFile ( file ) ) {
throw new FileNotFoundException ( file . toString ( ) + " (permission denied)" ) ;
}
}
private boolean canWritePosixFile ( File file ) throws IOException {
try {
Set < PosixFilePermission > permissions = Files
. getPosixFilePermissions ( file . toPath ( ) ) ;
for ( PosixFilePermission permission : WRITE_PERMISSIONS ) {
if ( permissions . contains ( permission ) ) {
return true ;
}
}
return false ;
}
catch ( UnsupportedOperationException ex ) {
// Assume that we can
return true ;
}
}
}