---

# (DD14) Business Logic — Example.lines() [7 LOC]

| Field | Value |
|-------|-------|
| Fully Qualified Name | `io.github.biezhi.java11.string.Example` |
| Layer | Utility |
| Module | `string` (Package: `io.github.biezhi.java11.string`) |

## 1. Role

### Example.lines()

This method is a small demonstration entry point for the Java 11 `String.lines()` API. It prepares a sample multi-line string, invokes the JDK line-splitting operation, and prints the resulting list of lines to the console so that developers can observe the runtime behavior of the API. Business-wise, it serves as a tutorial/sample utility rather than a domain transaction, request handler, or persistence workflow.

The method follows a simple presentation pattern: it first writes a header for the sample output, then sets up test content containing explicit line separators, and finally routes the content through `String.lines()` and `Collectors.toList()` before printing the result. There are no conditional branches, loops, or external service integrations. Its role in the larger system is to provide a reproducible example of JDK string processing that can be executed from `main()` and used as a reference for other string-related examples in the module.

## 2. Processing Pattern (Detailed Business Logic)

```mermaid
flowchart TD
    START(["lines()"])
    WRITE_HEADER(["writeHeader(\"String.lines()\")"])
    SET_STR(["Set sample multiline string"])
    CALL_LINES(["str.lines()"])
    CALL_COLLECT(["collect(Collectors.toList())"])
    CALL_PRINT(["System.out.println(result)"])
    END_NODE(["Return"])

    START --> WRITE_HEADER
    WRITE_HEADER --> SET_STR
    SET_STR --> CALL_LINES
    CALL_LINES --> CALL_COLLECT
    CALL_COLLECT --> CALL_PRINT
    CALL_PRINT --> END_NODE
```

**CRITICAL — Constant Resolution:**
No project constants are referenced by this method. The only literal text is the display header string `"String.lines()"`, which is not a constant definition from a separate file.

## 3. Parameter Analysis

| No | Parameter Name | Type | Business Description |
|----|---------------|------|---------------------|
| - | (none) | - | This method accepts no parameters. It is a self-contained sample routine that uses only local demo data and inherited/static helper behavior. |

External state read by the method:
- Static helper `writeHeader(...)` from the same class.
- Local demo string literal containing line breaks.
- Standard output stream via `System.out.println(...)`.

## 4. CRUD Operations / Called Services

### Pre-computed evidence from code analysis graph:

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| - | `Example.writeHeader` | Example | - | Calls `writeHeader` in `Example` |

Analyze all method calls within this method and classify each as a CRUD operation.
Use the pre-computed evidence above. If SC Code or Entity/DB is missing, try to infer from:
- The **SC Code** (Service Component code, e.g., `EKK0361A010SC`, `EKK1081D010CBS`) — look at the class name of the called method or its containing class.
- The **Entity/DB tables** — search for table name constants (often `KK_T_*` pattern), SQL references, or entity names in the called method's source code.

| CRUD | SC / CBS | SC Code | Entity / DB | Operation Description |
|------|----------|---------|-------------|----------------------|
| - | `writeHeader` | Example | - | Writes a descriptive console header for the sample execution. |
| - | `String.lines()` | JDK String API | - | Splits the sample string into line sequences using the Java 11 standard library. |
| - | `Collectors.toList()` | JDK Collectors API | - | Materializes the stream of lines into a list for display. |
| - | `System.out.println` | JDK Standard Output | - | Prints the collected line list to the console for demonstration purposes. |

## 5. Dependency Trace

### Pre-computed evidence from code analysis graph:

No screen/batch entry points found within 8 hops. Direct callers found: 1 methods.
Terminal operations from this method: `writeHeader` [-]

Trace who calls this method and what this method ultimately calls.
Use the pre-computed evidence and caller search results from Step 2 above.

| # | Caller (Screen/Batch) | Call Chain (Full Path to this Method) | Terminal (SC / CRUD / Entity) |
|---|----------------------|--------------------------------------|-------------------------------|
| 1 | Batch-like entry point: `Example.main` | `Example.main` -> `Example.lines` | `writeHeader [R] -`, `String.lines() [R] -`, `Collectors.toList() [R] -`, `System.out.println [R] -` |

## 6. Per-Branch Detail Blocks

The method has a single straight-through execution path with no branches.

**Block 1** — [SEQUENCE] (L96-L102)

> Demonstrates the Java 11 `String.lines()` API using a hard-coded sample string and console output.

| # | Type | Code |
|---|------|------|
| 1 | CALL | `writeHeader("String.lines()");` |
| 2 | SET | `String str = "Hello 
 World, I,m
biezhi.";` |
| 3 | CALL | `str.lines()` |
| 4 | CALL | `collect(Collectors.toList())` |
| 5 | CALL | `System.out.println(...)` |
| 6 | RETURN | `return;` |

## 7. Glossary

| Term | Type | Business Meaning |
|------|------|------------------|
| `String.lines()` | Technical API | Java 11 standard library method that splits a string into a stream of lines based on line terminators. |
| `Collectors.toList()` | Technical API | Stream collector that converts a stream into a list for display or further processing. |
| `writeHeader` | Helper method | Local utility used to print a formatted title for the demonstration output. |
| `System.out.println` | Technical API | Standard console output used to show the example result. |
| `main` | Entry point | Application entry point that invokes the sample methods in the class. |
| `line separator` | Technical term | A newline delimiter inside the sample text used to demonstrate line splitting. |
| `JDK 11` | Platform | Java development kit version that introduced the `String.lines()` API demonstrated here. |
| `Utility` | Layer | A non-business helper class that contains demonstration and sample code rather than domain transaction logic. |