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Class JarSigner

java.lang.Object

jdk.security.jarsigner.JarSigner

public final class JarSigner extends Object

An immutable utility class to sign a jar file.

A caller creates a JarSigner.Builder object, (optionally) sets some parameters, and calls build to create a JarSigner object. This JarSigner object can then be used to sign a jar file.

Unless otherwise stated, calling a method of JarSigner or JarSigner.Builder with a null argument will throw a NullPointerException.

Example:

    JarSigner signer = new JarSigner.Builder(key, certPath)
            .digestAlgorithm("SHA-256")
            .signatureAlgorithm("SHA256withRSA")
            .build();
    try (ZipFile  in = new ZipFile(inputFile);
            FileOutputStream out = new FileOutputStream(outputFile)) {
        signer.sign(in, out);
    }

Since:: 9

Nested Class Summary

Modifier and Type	Class	Description
`static class`	`JarSigner.Builder`	A mutable builder class that can create an immutable `JarSigner` from various signing-related parameters.

Method Summary

Modifier and Type	Method	Description
`String`	`getDigestAlgorithm()`	Returns the digest algorithm for this `JarSigner`.
`String`	`getProperty(String key)`	Returns the value of an additional implementation-specific property indicated by the specified key.
`String`	`getSignatureAlgorithm()`	Returns the signature algorithm for this `JarSigner`.
`String`	`getSignerName()`	Returns the signer name of this `JarSigner`.
`URI`	`getTsa()`	Returns the URI of the Time Stamping Authority (TSA).
`void`	`sign(ZipFile file, OutputStream os)`	Signs a file into an `OutputStream`.

Methods declared in class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

sign

public void sign(ZipFile file, OutputStream os)

Signs a file into an OutputStream. This method will not close file or os.

If an I/O error or signing error occurs during the signing, then it may do so after some bytes have been written. Consequently, the output stream may be in an inconsistent state. It is strongly recommended that it be promptly closed in this case.

Parameters:: file - the file to sign.; os - the output stream.
Throws:: JarSignerException - if the signing fails.

getDigestAlgorithm

public String getDigestAlgorithm()

Returns the digest algorithm for this JarSigner.

The return value is never null.

Returns:: the digest algorithm.

getSignatureAlgorithm

public String getSignatureAlgorithm()

Returns the signature algorithm for this JarSigner.

The return value is never null.

Returns:: the signature algorithm.

getTsa

public URI getTsa()

Returns the URI of the Time Stamping Authority (TSA).

Returns:: the URI of the TSA.

getSignerName

public String getSignerName()

Returns the signer name of this JarSigner.

The return value is never null.

Returns:: the signer name.

getProperty

public String getProperty(String key)

Returns the value of an additional implementation-specific property indicated by the specified key. If a property is not set but has a default value, the default value will be returned.

Implementation Note:: See JarSigner.Builder.setProperty(java.lang.String, java.lang.String) for a list of properties this implementation supports. All property names are case-insensitive.
Parameters:: key - the name of the property.
Returns:: the value for the property.
Throws:: UnsupportedOperationException - if the key is not supported by this implementation.

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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/jdk.jartool/jdk/security/jarsigner/JarSigner.html