gm4java - trying to get multiple images in 1 gm process

gm4java_mult_im_sing_proc.scala

// Failed attempts to process several images within a single gm process
// some of these are silly, but I was desperate

val config = new GMConnectionPoolConfig()
val service = new PooledGMService(config)
val command = new GMBatchCommand(service, "convert")

// Q1. can we make GMBatchCommand run an operation with multiple images in it?
val a = Files.createTempFile("thumbnail", ".jpg").toString
val aa = Files.createTempFile("thumbnail", ".jpg").toString

val op1 = new GMOperation()
op1.addImage("/Users/artsyinc/Documents/doublet/test_images/100_w_matt/grioc0000030-D.jpg")
op1.resize(200, 200)
op1.addImage(a)
op1.addImage("/Users/artsyinc/Documents/doublet/test_images/100_w_matt/grioc0001416-D.jpg")
op1.resize(200, 200)
op1.addImage(aa)
command.run(op1)

// A.
// org.im4java.core.CommandException: org.im4java.core.CommandException: convert: Empty input file (/var/folders/sz/v9p5w7d912182q3mtj_gy_j40000gp/T/thumbnail983933003158565220.jpg).
// This is the 2nd tmp image

// Q2. can we do the above with an explicit convert statement?
val b = Files.createTempFile("thumbnail", ".jpg").toString
val bb = Files.createTempFile("thumbnail", ".jpg").toString
val op2 = new GMOperation()
op2.addImage("/Users/artsyinc/Documents/doublet/test_images/100_w_matt/grioc0000030-D.jpg")
op2.resize(200, 200)
op2.addImage(b)
op2.addRawArg("convert")
op2.addImage("/Users/artsyinc/Documents/doublet/test_images/100_w_matt/grioc0001416-D.jpg")
op2.resize(200, 200)
op2.addImage(bb)
command.run(op2)

// A.
// org.im4java.core.CommandException: java.io.IOException: convert: Unable to open file (convert) [No such file or directory].

// Q3. will the run method for GMBatchCommand take several GMOperation arguments
// A.
// java.lang.IllegalArgumentException: more argument images than placeholders!

// Q4. will the run method for GMBatchCommand take a linked list of arguments?
// A.
// <console>:31: error: type mismatch;
//  found   : java.util.LinkedList[org.gm4java.im4java.GMOperation]
//  required: org.im4java.core.Operation
//               command.run(opss)


// Q5. can we add multiple commands in sequence to a PooledGMService?
val t = Files.createTempFile("thumbnail", ".jpg").toString
val tt = Files.createTempFile("thumbnail", ".jpg").toString
service.execute("convert",
    "/Users/artsyinc/Documents/doublet/test_images/100_w_matt/grioc0000030-D.jpg",
    "-resize",
    "200x200",
    t,
    "/Users/artsyinc/Documents/doublet/test_images/100_w_matt/grioc0001416-D.jpg",
    "-resize",
    "200x200",
    tt)

// A.
// org.gm4java.engine.GMException: convert: Empty input file (/var/folders/sz/v9p5w7d912182q3mtj_gy_j40000gp/T/thumbnail4276570003656926961.jpg)
// This is the 2nd tmp image

// Q6. Should I repeat the above with an extra "convert" argument?
val n = Files.createTempFile("thumbnail", ".jpg").toString
val nn = Files.createTempFile("thumbnail", ".jpg").toString
service.execute("convert",
    "/Users/artsyinc/Documents/doublet/test_images/100_w_matt/grioc0000030-D.jpg",
    "-resize",
    "200x200",
    n,
    "convert",
    "/Users/artsyinc/Documents/doublet/test_images/100_w_matt/grioc0001416-D.jpg",
    "-resize",
    "200x200",
    nn)

// A.
// java.io.IOException: convert: Unable to open file (convert) [No such file or directory].

// Q7. can we execute the batch command explicitly?
val v = Files.createTempFile("thumbnail", ".jpg").toString
val vv = Files.createTempFile("thumbnail", ".jpg").toString

service.execute("batch", "convert", "/Users/me/test_images/grioc0000030-D.jpg", "-resize", "200x200", v, "convert", "/Users/me/test_images/grioc0001416-D.jpg", "-resize", "200x200", vv)

// A.
// org.gm4java.engine.GMException: gm: Unrecognized command 'batch'.

A1: It's not about how many image files, one GMOperation should be exactly one GM command. In this case, you can only add as much as what you can enter in one convert command. But you can reuse GMOperation instance with different images, see im4java documentation for detail.
A2: No, you cannot, for the same reason as Q1.
A3, A4: See documentation http://im4java.sourceforge.net/api/org/im4java/core/ImageCommand.html#run%28org.im4java.core.Operation,%20java.lang.Object...%29
A5, A6, A7: One execute call is strictly one GM command. If you need to execute multiple commands, make multiple calls.