how to read file from temp folder

Question

Hi, need suggestion how to read file from shared folder in ibm bpm server. i have create script to write file in service flow but there is no sample to read file from share folder.

//Below code converts the file content string in to byte[] (byte array).

var byteValue = Packages.java.lang.String(tw.local.ContentStream.content).getBytes();

// Below code, decodes the above Base64 byte array in to use format of byte[] (byte array)

var content64 = Packages.org.apache.commons.codec.binary.Base64.decodeBase64(byteValue);

    var fileName="/opt/docs/" + tw.local.ContentStream.fileName ;

            var file = new Packages.java.io.File(fileName);

             // if file doesnt exists, then create it

            if (!file.exists()) {

                file.createNewFile();

            }

            

          //change permission to 777 for all the users

        //no option for group and others file.setExecutable(true, false);

        file.setReadable(true, false);

       file.setWritable(true, false);

            var fop = new Packages.java.io.FileOutputStream(file);

            fop.write(content64);

Thank you,
 

Answer 1

Server-side JavaScript in BPM / BAW has no file API of its own, but it can call Java classes directly (Rhino "LiveConnect"), so reading a file from a folder the server can reach is a few lines - no jar required:

// service flow script task - read a text file from a shared folder mounted on the server
var path = tw.env.inboundFolder + "/" + tw.local.fileName;      // e.g. /mnt/share/in/order-123.csv
var file = new java.io.File(path);
if (!file.exists()) throw new Error("File not found: " + path);
var bytes = java.nio.file.Files.readAllBytes(file.toPath());
tw.local.content = String(new java.lang.String(bytes, "UTF-8"));  // text
// binary (PDF, image): keep it as Base64 for the document store
tw.local.contentBase64 = String(java.util.Base64.getEncoder().encodeToString(bytes));

// list a folder
var names = new java.io.File(tw.env.inboundFolder).list();
tw.local.files = new tw.object.listOf.String();
for (var i = 0; i < names.length; i++) tw.local.files[i] = String(names[i]);

Write works the same way (java.nio.file.Files.write(java.nio.file.Paths.get(path), new java.lang.String(tw.local.content).getBytes("UTF-8"))). Notes:

• The path is on the server that runs the service (every cluster member must see the share - mount it identically on all nodes, or use a Java integration on one node).
• Wrap Java strings with String(...) before storing them in tw.local, otherwise you keep a java.lang.String object inside the variable.
• Large files: stream with java.io.BufferedReader line by line instead of readAllBytes.
• On CP4BA (containers) there is no shared folder unless you mount a persistent volume into the BAW pods - the supported pattern there is to read from an ECM object store or an object storage (S3) through REST.
• Some hardened servers disable Java access from scripts (CWTBG0529E / script security); then use a Java integration with a small class in a managed jar.

References

• JavaScript API reference (server-side scripting, Java access)
• BAW documentation - Java integration in service flows