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package java.util.jar;

import java.io.FilterInputStream;
import java.io.DataOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.util.Map;
import java.util.HashMap;
import java.util.Iterator;

The Manifest class is used to maintain Manifest entry names and their associated Attributes. There are main Manifest Attributes as well as per-entry Attributes. For information on the Manifest format, please see the Manifest format specification.
Author: David Connelly
See Also:
Since: 1.2
/** * The Manifest class is used to maintain Manifest entry names and their * associated Attributes. There are main Manifest Attributes as well as * per-entry Attributes. For information on the Manifest format, please * see the * <a href="../../../../technotes/guides/jar/jar.html"> * Manifest format specification</a>. * * @author David Connelly * @see Attributes * @since 1.2 */
public class Manifest implements Cloneable { // manifest main attributes private final Attributes attr = new Attributes(); // manifest entries private final Map<String, Attributes> entries = new HashMap<>(); // associated JarVerifier, not null when called by JarFile::getManifest. private final JarVerifier jv;
Constructs a new, empty Manifest.
/** * Constructs a new, empty Manifest. */
public Manifest() { jv = null; }
Constructs a new Manifest from the specified input stream.
Params:
  • is – the input stream containing manifest data
Throws:
/** * Constructs a new Manifest from the specified input stream. * * @param is the input stream containing manifest data * @throws IOException if an I/O error has occurred */
public Manifest(InputStream is) throws IOException { this(null, is); }
Constructs a new Manifest from the specified input stream and associates it with a JarVerifier.
/** * Constructs a new Manifest from the specified input stream * and associates it with a JarVerifier. */
Manifest(JarVerifier jv, InputStream is) throws IOException { read(is); this.jv = jv; }
Constructs a new Manifest that is a copy of the specified Manifest.
Params:
  • man – the Manifest to copy
/** * Constructs a new Manifest that is a copy of the specified Manifest. * * @param man the Manifest to copy */
public Manifest(Manifest man) { attr.putAll(man.getMainAttributes()); entries.putAll(man.getEntries()); jv = man.jv; }
Returns the main Attributes for the Manifest.
Returns:the main Attributes for the Manifest
/** * Returns the main Attributes for the Manifest. * @return the main Attributes for the Manifest */
public Attributes getMainAttributes() { return attr; }
Returns a Map of the entries contained in this Manifest. Each entry is represented by a String name (key) and associated Attributes (value). The Map permits the null key, but no entry with a null key is created by read, nor is such an entry written by using write.
Returns:a Map of the entries contained in this Manifest
/** * Returns a Map of the entries contained in this Manifest. Each entry * is represented by a String name (key) and associated Attributes (value). * The Map permits the {@code null} key, but no entry with a null key is * created by {@link #read}, nor is such an entry written by using {@link * #write}. * * @return a Map of the entries contained in this Manifest */
public Map<String,Attributes> getEntries() { return entries; }
Returns the Attributes for the specified entry name. This method is defined as:
     return (Attributes)getEntries().get(name)
Though null is a valid name, when getAttributes(null) is invoked on a Manifest obtained from a jar file, null will be returned. While jar files themselves do not allow null-named attributes, it is possible to invoke getEntries on a Manifest, and on that result, invoke put with a null key and an arbitrary value. Subsequent invocations of getAttributes(null) will return the just-put value.

Note that this method does not return the manifest's main attributes; see getMainAttributes.

Params:
  • name – entry name
Returns:the Attributes for the specified entry name
/** * Returns the Attributes for the specified entry name. * This method is defined as: * <pre> * return (Attributes)getEntries().get(name) * </pre> * Though {@code null} is a valid {@code name}, when * {@code getAttributes(null)} is invoked on a {@code Manifest} * obtained from a jar file, {@code null} will be returned. While jar * files themselves do not allow {@code null}-named attributes, it is * possible to invoke {@link #getEntries} on a {@code Manifest}, and * on that result, invoke {@code put} with a null key and an * arbitrary value. Subsequent invocations of * {@code getAttributes(null)} will return the just-{@code put} * value. * <p> * Note that this method does not return the manifest's main attributes; * see {@link #getMainAttributes}. * * @param name entry name * @return the Attributes for the specified entry name */
public Attributes getAttributes(String name) { return getEntries().get(name); }
Returns the Attributes for the specified entry name, if trusted.
Params:
  • name – entry name
Throws:
  • SecurityException – if the associated jar is signed but this entry has been modified after signing (i.e. the section in the manifest does not exist in SF files of all signers).
Returns:returns the same result as getAttributes(String)
/** * Returns the Attributes for the specified entry name, if trusted. * * @param name entry name * @return returns the same result as {@link #getAttributes(String)} * @throws SecurityException if the associated jar is signed but this entry * has been modified after signing (i.e. the section in the manifest * does not exist in SF files of all signers). */
Attributes getTrustedAttributes(String name) { // Note: Before the verification of MANIFEST.MF/.SF/.RSA files is done, // jv.isTrustedManifestEntry() isn't able to detect MANIFEST.MF change. // Users of this method should call SharedSecrets.javaUtilJarAccess() // .ensureInitialization() first. Attributes result = getAttributes(name); if (result != null && jv != null && ! jv.isTrustedManifestEntry(name)) { throw new SecurityException("Untrusted manifest entry: " + name); } return result; }
Clears the main Attributes as well as the entries in this Manifest.
/** * Clears the main Attributes as well as the entries in this Manifest. */
public void clear() { attr.clear(); entries.clear(); }
Writes the Manifest to the specified OutputStream. Attributes.Name.MANIFEST_VERSION must be set in MainAttributes prior to invoking this method.
Params:
  • out – the output stream
Throws:
See Also:
/** * Writes the Manifest to the specified OutputStream. * Attributes.Name.MANIFEST_VERSION must be set in * MainAttributes prior to invoking this method. * * @param out the output stream * @exception IOException if an I/O error has occurred * @see #getMainAttributes */
public void write(OutputStream out) throws IOException { DataOutputStream dos = new DataOutputStream(out); // Write out the main attributes for the manifest attr.writeMain(dos); // Now write out the pre-entry attributes Iterator<Map.Entry<String, Attributes>> it = entries.entrySet().iterator(); while (it.hasNext()) { Map.Entry<String, Attributes> e = it.next(); StringBuffer buffer = new StringBuffer("Name: "); String value = e.getKey(); if (value != null) { byte[] vb = value.getBytes("UTF8"); value = new String(vb, 0, 0, vb.length); } buffer.append(value); buffer.append("\r\n"); make72Safe(buffer); dos.writeBytes(buffer.toString()); e.getValue().write(dos); } dos.flush(); }
Adds line breaks to enforce a maximum 72 bytes per line.
/** * Adds line breaks to enforce a maximum 72 bytes per line. */
static void make72Safe(StringBuffer line) { int length = line.length(); if (length > 72) { int index = 70; while (index < length - 2) { line.insert(index, "\r\n "); index += 72; length += 3; } } return; }
Reads the Manifest from the specified InputStream. The entry names and attributes read will be merged in with the current manifest entries.
Params:
  • is – the input stream
Throws:
/** * Reads the Manifest from the specified InputStream. The entry * names and attributes read will be merged in with the current * manifest entries. * * @param is the input stream * @exception IOException if an I/O error has occurred */
public void read(InputStream is) throws IOException { // Buffered input stream for reading manifest data FastInputStream fis = new FastInputStream(is); // Line buffer byte[] lbuf = new byte[512]; // Read the main attributes for the manifest attr.read(fis, lbuf); // Total number of entries, attributes read int ecount = 0, acount = 0; // Average size of entry attributes int asize = 2; // Now parse the manifest entries int len; String name = null; boolean skipEmptyLines = true; byte[] lastline = null; while ((len = fis.readLine(lbuf)) != -1) { if (lbuf[--len] != '\n') { throw new IOException("manifest line too long"); } if (len > 0 && lbuf[len-1] == '\r') { --len; } if (len == 0 && skipEmptyLines) { continue; } skipEmptyLines = false; if (name == null) { name = parseName(lbuf, len); if (name == null) { throw new IOException("invalid manifest format"); } if (fis.peek() == ' ') { // name is wrapped lastline = new byte[len - 6]; System.arraycopy(lbuf, 6, lastline, 0, len - 6); continue; } } else { // continuation line byte[] buf = new byte[lastline.length + len - 1]; System.arraycopy(lastline, 0, buf, 0, lastline.length); System.arraycopy(lbuf, 1, buf, lastline.length, len - 1); if (fis.peek() == ' ') { // name is wrapped lastline = buf; continue; } name = new String(buf, 0, buf.length, "UTF8"); lastline = null; } Attributes attr = getAttributes(name); if (attr == null) { attr = new Attributes(asize); entries.put(name, attr); } attr.read(fis, lbuf); ecount++; acount += attr.size(); //XXX: Fix for when the average is 0. When it is 0, // you get an Attributes object with an initial // capacity of 0, which tickles a bug in HashMap. asize = Math.max(2, acount / ecount); name = null; skipEmptyLines = true; } } private String parseName(byte[] lbuf, int len) { if (toLower(lbuf[0]) == 'n' && toLower(lbuf[1]) == 'a' && toLower(lbuf[2]) == 'm' && toLower(lbuf[3]) == 'e' && lbuf[4] == ':' && lbuf[5] == ' ') { try { return new String(lbuf, 6, len - 6, "UTF8"); } catch (Exception e) { } } return null; } private int toLower(int c) { return (c >= 'A' && c <= 'Z') ? 'a' + (c - 'A') : c; }
Returns true if the specified Object is also a Manifest and has the same main Attributes and entries.
Params:
  • o – the object to be compared
Returns:true if the specified Object is also a Manifest and has the same main Attributes and entries
/** * Returns true if the specified Object is also a Manifest and has * the same main Attributes and entries. * * @param o the object to be compared * @return true if the specified Object is also a Manifest and has * the same main Attributes and entries */
public boolean equals(Object o) { if (o instanceof Manifest) { Manifest m = (Manifest)o; return attr.equals(m.getMainAttributes()) && entries.equals(m.getEntries()); } else { return false; } }
Returns the hash code for this Manifest.
/** * Returns the hash code for this Manifest. */
public int hashCode() { return attr.hashCode() + entries.hashCode(); }
Returns a shallow copy of this Manifest. The shallow copy is implemented as follows:
    public Object clone() { return new Manifest(this); }
Returns:a shallow copy of this Manifest
/** * Returns a shallow copy of this Manifest. The shallow copy is * implemented as follows: * <pre> * public Object clone() { return new Manifest(this); } * </pre> * @return a shallow copy of this Manifest */
public Object clone() { return new Manifest(this); } /* * A fast buffered input stream for parsing manifest files. */ static class FastInputStream extends FilterInputStream { private byte buf[]; private int count = 0; private int pos = 0; FastInputStream(InputStream in) { this(in, 8192); } FastInputStream(InputStream in, int size) { super(in); buf = new byte[size]; } public int read() throws IOException { if (pos >= count) { fill(); if (pos >= count) { return -1; } } return Byte.toUnsignedInt(buf[pos++]); } public int read(byte[] b, int off, int len) throws IOException { int avail = count - pos; if (avail <= 0) { if (len >= buf.length) { return in.read(b, off, len); } fill(); avail = count - pos; if (avail <= 0) { return -1; } } if (len > avail) { len = avail; } System.arraycopy(buf, pos, b, off, len); pos += len; return len; } /* * Reads 'len' bytes from the input stream, or until an end-of-line * is reached. Returns the number of bytes read. */ public int readLine(byte[] b, int off, int len) throws IOException { byte[] tbuf = this.buf; int total = 0; while (total < len) { int avail = count - pos; if (avail <= 0) { fill(); avail = count - pos; if (avail <= 0) { return -1; } } int n = len - total; if (n > avail) { n = avail; } int tpos = pos; int maxpos = tpos + n; while (tpos < maxpos && tbuf[tpos++] != '\n') ; n = tpos - pos; System.arraycopy(tbuf, pos, b, off, n); off += n; total += n; pos = tpos; if (tbuf[tpos-1] == '\n') { break; } } return total; } public byte peek() throws IOException { if (pos == count) fill(); if (pos == count) return -1; // nothing left in buffer return buf[pos]; } public int readLine(byte[] b) throws IOException { return readLine(b, 0, b.length); } public long skip(long n) throws IOException { if (n <= 0) { return 0; } long avail = count - pos; if (avail <= 0) { return in.skip(n); } if (n > avail) { n = avail; } pos += n; return n; } public int available() throws IOException { return (count - pos) + in.available(); } public void close() throws IOException { if (in != null) { in.close(); in = null; buf = null; } } private void fill() throws IOException { count = pos = 0; int n = in.read(buf, 0, buf.length); if (n > 0) { count = n; } } } }