- 1). Create a file on your computer and name it "Count.java." Copy or download the source code sample to produce this file. This class file will need to access a text file with some data in it. You can create this easily with Notepad or any text editor program you may have. It is important that you place your text file into a directory different from the directory where you put your downloaded "count" class file. For example, "C:\TestData\data."
- 2). Compile and execute the "Count" component to see how it functions. To run the Count application successfully, you must define, to serve as an argument, the file's path name after the command. For example, "java Count C:\TestData\data." This way, the data will be made available to the application to be read promptly and to produce the results efficiently, as shown below.
C:\Test>java Count C:\TestData\data
Counted 65 chars. - 3). Type the following code in your command window to compose a Java Archive, or JAR file, that will contain the Count class file internally:
jar cvf Count.jar Count.class - 4). Input the following command in your command window to create a "keystore" and label it "examplestore":
keytool -genkey -alias signFiles -keystore examplestore
When you generate keys, you will be prompted to enter the keystore, which is "examplestore," and passwords for the key. - 5). Enter the following command in your command window to sign the JAR file "Count.jar" with the private key in the keystore entry. This element is called signFiles, and its purpose is to label the completed signed JAR file sCount.jar:
jarsigner -keystore examplestore -signedjar sCount.jar Count.jar signFiles
Again, you will have to enter the store password and the private key password to proceed. - 6). Copy the certificate from the keystore "examplestore" to a file labeled "Example.cer" with the following command:
keytool -export -keystore examplestore -alias signFiles -file Example.cer
The signature is authenticated when the Count application in the signed JAR file attempts to read a file and a policy file issues the signed code the proper permission.
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