Allow input streams to be read

3 files changed, 101 insertions, 12 deletions

diff --git a/src/main/java/org/zwobble/mammoth/Mammoth.java b/src/main/java/org/zwobble/mammoth/Mammoth.java
index 93c639a..4963c3a 100644
--- a/src/main/java/org/zwobble/mammoth/Mammoth.java
+++ b/src/main/java/org/zwobble/mammoth/Mammoth.java
@@ -7,6 +7,7 @@ import org.zwobble.mammoth.documents.HasChildren;
 import org.zwobble.mammoth.documents.Paragraph;
 import org.zwobble.mammoth.documents.Text;
 import org.zwobble.mammoth.docx.DocxFile;
+import org.zwobble.mammoth.docx.InMemoryDocxFile;
 import org.zwobble.mammoth.docx.ZippedDocxFile;
 import org.zwobble.mammoth.html.Html;
 import org.zwobble.mammoth.results.Result;
@@ -18,6 +19,8 @@ import org.zwobble.mammoth.util.Casts;
 
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
+import java.nio.file.Path;
 import java.util.List;
 import java.util.Optional;
 import java.util.zip.ZipFile;
@@ -61,30 +64,47 @@ public class Mammoth {
         .mapParagraph(ParagraphMatcher.styleName("Normal"), HtmlPath.element("p"))
         .build();
 
-    public static Result<String> convertToHtml(File file) {
+    public static Result<String> convertToHtml(InputStream stream) throws IOException {
+        return convertToHtml(stream, Options.DEFAULT);
+    }
+
+    public static Result<String> convertToHtml(InputStream stream, Options options) throws IOException {
+        return withDocxFile(stream, zipFile ->
+            convertToHtml(Optional.empty(), zipFile, options));
+    }
+
+    public static Result<String> convertToHtml(File file) throws IOException {
         return convertToHtml(file, Options.DEFAULT);
     }
 
-    public static Result<String> convertToHtml(File file, Options options) {
+    public static Result<String> convertToHtml(File file, Options options) throws IOException {
         return withDocxFile(file, zipFile ->
-            readDocument(Optional.of(file.toPath()), zipFile)
-                .flatMap(nodes -> DocumentConverter.convertToHtml(options.idPrefix, options.preserveEmptyParagraphs, DEFAULT_STYLE_MAP, nodes))
-                .map(Html::stripEmpty)
-                .map(Html::collapse)
-                .map(Html::write));
+            convertToHtml(Optional.of(file.toPath()), zipFile, options));
     }
 
-    public static Result<String> extractRawText(File file) {
+    private static Result<String> convertToHtml(Optional<Path> path, DocxFile zipFile, Options options) {
+        return readDocument(path, zipFile)
+            .flatMap(nodes -> DocumentConverter.convertToHtml(options.idPrefix, options.preserveEmptyParagraphs, DEFAULT_STYLE_MAP, nodes))
+            .map(Html::stripEmpty)
+            .map(Html::collapse)
+            .map(Html::write);
+    }
+
+    public static Result<String> extractRawText(File file) throws IOException {
         return withDocxFile(file, zipFile ->
             readDocument(Optional.of(file.toPath()), zipFile)
                 .map(Mammoth::extractRawTextOfChildren));
     }
 
-    private static <T> T withDocxFile(File file, Function<DocxFile, T> function) {
+    private static <T> T withDocxFile(File file, Function<DocxFile, T> function) throws IOException {
         try (DocxFile zipFile = new ZippedDocxFile(new ZipFile(file))) {
             return function.apply(zipFile);
-        } catch (IOException e) {
-            throw new UnsupportedOperationException("Should return a result of failure");
+        }
+    }
+
+    private static <T> T withDocxFile(InputStream stream, Function<DocxFile, T> function) throws IOException {
+        try (DocxFile zipFile = InMemoryDocxFile.fromStream(stream)) {
+            return function.apply(zipFile);
         }
     }
 
diff --git a/src/main/java/org/zwobble/mammoth/docx/DocumentReader.java b/src/main/java/org/zwobble/mammoth/docx/DocumentReader.java
index 284dd89..1fc0fc8 100644
--- a/src/main/java/org/zwobble/mammoth/docx/DocumentReader.java
+++ b/src/main/java/org/zwobble/mammoth/docx/DocumentReader.java
@@ -7,6 +7,9 @@ import org.zwobble.mammoth.util.MammothLists;
 import org.zwobble.mammoth.xml.XmlElement;
 
 import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.net.URISyntaxException;
 import java.nio.file.Path;
 import java.util.Optional;
 
@@ -24,7 +27,14 @@ public class DocumentReader {
         ContentTypes contentTypes = readContentTypes(zipFile);
         FileReader fileReader = uri -> {
             try {
-                return path.get().toUri().resolve(uri).toURL().openStream();
+                Optional<URI> absoluteUri = asAbsoluteUri(uri);
+                if (absoluteUri.isPresent()) {
+                    return open(absoluteUri.get());
+                } else if (path.isPresent()) {
+                    return open(path.get().toUri().resolve(uri));
+                } else {
+                    throw new IOException("path of document is unknown, but is required for relative URI");
+                }
             } catch (IOException exception) {
                 throw new IOException("could not open external image '" + uri + "': " + exception.getMessage());
             }
@@ -40,6 +50,19 @@ public class DocumentReader {
             });
     }
 
+    private static InputStream open(URI uri) throws IOException {
+        return uri.toURL().openStream();
+    }
+
+    private static Optional<URI> asAbsoluteUri(String uriString) {
+        try {
+            URI uri = new URI(uriString);
+            return uri.isAbsolute() ? Optional.of(uri) : Optional.empty();
+        } catch (URISyntaxException exception) {
+            return Optional.empty();
+        }
+    }
+
     private static Result<Notes> readNotes(DocxFile file, BodyReaders bodyReaders) {
         return Result.map(
             tryParseOfficeXml(file, "word/footnotes.xml")
diff --git a/src/main/java/org/zwobble/mammoth/docx/InMemoryDocxFile.java b/src/main/java/org/zwobble/mammoth/docx/InMemoryDocxFile.java
new file mode 100644
index 0000000..3c6d4b4
--- /dev/null
+++ b/src/main/java/org/zwobble/mammoth/docx/InMemoryDocxFile.java
@@ -0,0 +1,46 @@
+package org.zwobble.mammoth.docx;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Maps;
+import com.google.common.io.ByteStreams;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
+import java.util.Map;
+import java.util.Optional;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+public class InMemoryDocxFile implements DocxFile {
+    public static DocxFile fromStream(InputStream stream) throws IOException {
+        ZipInputStream zipStream = new ZipInputStream(stream);
+        ImmutableMap.Builder<String, byte[]> entries = ImmutableMap.builder();
+        ZipEntry entry;
+        while ((entry = zipStream.getNextEntry()) != null) {
+            entries.put(entry.getName(), ByteStreams.toByteArray(zipStream));
+        }
+        return new InMemoryDocxFile(entries.build());
+    }
+
+    public static DocxFile fromStrings(Map<String, String> entries) {
+        return new InMemoryDocxFile(Maps.transformValues(entries, value -> value.getBytes(StandardCharsets.UTF_8)));
+    }
+
+    private final Map<String, byte[]> entries;
+
+    public InMemoryDocxFile(Map<String, byte[]> entries) {
+        this.entries = entries;
+    }
+
+    @Override
+    public Optional<InputStream> tryGetInputStream(String name) throws IOException {
+        return Optional.ofNullable(entries.get(name))
+            .map(ByteArrayInputStream::new);
+    }
+
+    @Override
+    public void close() throws IOException {
+    }
+}