Support files opened via Files#newBufferedWriter (#161)

Co-authored-by: Basil Crow <[email protected]>

pom.xml

@@ -43,6 +43,17 @@
       <artifactId>args4j</artifactId>
       <version>2.33</version>
     </dependency>
+    <dependency>
+      <groupId>com.github.spotbugs</groupId>
+      <artifactId>spotbugs-annotations</artifactId>
+      <optional>true</optional>
+      <exclusions>
+        <exclusion>
+          <groupId>com.google.code.findbugs</groupId>
+          <artifactId>jsr305</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
     <dependency>
       <groupId>org.ow2.asm</groupId>
       <artifactId>asm</artifactId>

src/main/java/org/kohsuke/file_leak_detector/AgentMain.java

@@ -2,6 +2,7 @@
 
 import java.io.BufferedReader;
 import java.io.File;
+import java.io.FileDescriptor;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
@@ -146,6 +147,7 @@ public void run() {
                 Files.class);
 
         addIfFound(classes, "sun.nio.ch.SocketChannelImpl");
+        addIfFound(classes, "sun.nio.ch.FileChannelImpl");
         addIfFound(classes, "java.net.AbstractPlainSocketImpl");
         addIfFound(classes, "java.net.PlainSocketImpl");
         addIfFound(classes, "sun.nio.fs.UnixDirectoryStream");
@@ -370,6 +372,25 @@ static List<ClassTransformSpec> createSpec() {
                         "(Ljava/nio/channels/spi/SelectorProvider;Ljava/io/FileDescriptor;Ljava/net/InetSocketAddress;)V"),
                 new OpenSocketInterceptor("<init>", "(Ljava/nio/channels/spi/SelectorProvider;)V"),
                 new CloseInterceptor("kill")));
+        spec.add(new ClassTransformSpec(
+                "sun/nio/ch/FileChannelImpl",
+                new ReturnFromStaticMethodInterceptor(
+                        "open",
+                        "(Ljava/io/FileDescriptor;Ljava/lang/String;ZZZLjava/io/Closeable;)Ljava/nio/channels/FileChannel;",
+                        4,
+                        "openFileString",
+                        Object.class,
+                        FileDescriptor.class,
+                        String.class),
+                // this is for java 11/17 - which use Object instead of Closeable as the last parameter
+                new ReturnFromStaticMethodInterceptor(
+                        "open",
+                        "(Ljava/io/FileDescriptor;Ljava/lang/String;ZZZLjava/lang/Object;)Ljava/nio/channels/FileChannel;",
+                        4,
+                        "openFileString",
+                        Object.class,
+                        FileDescriptor.class,
+                        String.class)));
         return spec;
     }
 

src/main/java/org/kohsuke/file_leak_detector/Listener.java

@@ -1,6 +1,8 @@
 package org.kohsuke.file_leak_detector;
 
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
 import java.io.File;
+import java.io.FileDescriptor;
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.OutputStream;
@@ -21,6 +23,7 @@
 import java.nio.charset.Charset;
 import java.nio.file.DirectoryStream;
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Date;
 import java.util.LinkedHashMap;
@@ -343,6 +346,15 @@ public static synchronized void open(Object _this, Path p) {
         }
     }
 
+    @SuppressFBWarnings(
+            value = "PATH_TRAVERSAL_IN",
+            justification = "path comes from sun.nio.fs.UnixChannelFactory.newFileChannel(int, sun.nio.fs.UnixPath, "
+                    + "java.lang.String, java.util.Set<? extends java.nio.file.OpenOption>, int). At this point, the path "
+                    + "is not controlled by the user.")
+    public static synchronized void openFileString(Object _this, FileDescriptor fileDescriptor, String path) {
+        open(_this, Paths.get(path));
+    }
+
     /**
      * Called when a pipe is opened, e.g. via SelectorProvider
      *

src/test/java/org/kohsuke/file_leak_detector/instrumented/FileDemo.java

@@ -8,6 +8,8 @@
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
@@ -135,6 +137,34 @@ public void openCloseFile() throws Exception {
         assertThat(traceOutput, containsString("Closed " + tempFile));
     }
 
+    @Test
+    public void openCloseFilesBufferedWriter() throws Exception {
+        try (BufferedWriter writer = Files.newBufferedWriter(tempFile.toPath())) {
+            assertNotNull(writer);
+            assertNotNull("No file record for file=" + tempFile + " found", findPathRecord(tempFile.toPath()));
+            assertThat("Did not have the expected type of 'marker' object: " + obj, obj, instanceOf(FileChannel.class));
+        }
+        assertNull("File record for file=" + tempFile + " not removed", findPathRecord(tempFile.toPath()));
+
+        String traceOutput = output.toString();
+        assertThat(traceOutput, containsString("Opened " + tempFile));
+        assertThat(traceOutput, containsString("Closed " + tempFile));
+    }
+
+    @Test
+    public void openCloseFilesBufferedReader() throws Exception {
+        try (BufferedReader reader = Files.newBufferedReader(tempFile.toPath())) {
+            assertNotNull(reader);
+            assertNotNull("No file record for file=" + tempFile + " found", findPathRecord(tempFile.toPath()));
+            assertThat("Did not have the expected type of 'marker' object: " + obj, obj, instanceOf(FileChannel.class));
+        }
+        assertNull("File record for file=" + tempFile + " not removed", findPathRecord(tempFile.toPath()));
+
+        String traceOutput = output.toString();
+        assertThat(traceOutput, containsString("Opened " + tempFile));
+        assertThat(traceOutput, containsString("Closed " + tempFile));
+    }
+
     @Test
     public void openCloseFileChannel() throws Exception {
         try (FileChannel fileChannel = FileChannel.open(tempFile.toPath(), StandardOpenOption.APPEND)) {