http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); he:z9EG}
} W$()W)
for(int i=0;i<nEndPos.length-1;i++) `wQs$!a
{ }f14# y;
nEndPos = nStartPos[i+1]; xkax
} G6}&k[d5%
nEndPos[nEndPos.length-1] = nFileLength; DwZRx@
} URg;e M#
} :#35mBe}k
w0lgB%97p
(Y8LyY
//启动子线程 =QbOvIq
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; nE*S3
for(int i=0;i<nStartPos.length;i++) sQ,xTWdj
{ LExm#T`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !{+.)%d'g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), '`.-75T
nStartPos,nEndPos,i); v9Sk\9}S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 32?'jRN(ue
fileSplitterFetch.start(); / o I 4&W
} /3K)$Er
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 19c_=$mV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); &qWB\m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -gS9I^
nEndPos = " + nFileLength); P}UxA!
// fileSplitterFetch[nPos.length-1].start(); H9_iTGBQ
2f@Cy+W'[
m'"H1~BW
//等待子线程结束 l>`66~+s,`
//int count = 0; }^$1<GT
//是否结束while循环 Ry"4v_e9
boolean breakWhile = false; #+V4<o
cL~WDW/
-,T!/E
while(!bStop) V,0$mBYa
{ Wf"GA i
write_nPos(); OKK Ko`RN
Utility.sleep(500); D4|Ajeo;1
breakWhile = true; /4 OmnE;
"~._G5i.
{i?G:K
for(int i=0;i<nStartPos.length;i++) ge.>#1f}
{ KK2YT/K$SG
if(!fileSplitterFetch.bDownOver) !4=_l6kg~+
{ ^v'0\(H?P
breakWhile = false; G.~Q2O#T
break; REE.8_
} L6fbR-&Lt
} strM3j##x
if(breakWhile) 2,`X@N`\
break; $fT5Vc]B4
f\_PNZCc
3nc\6v%
//count++; O6)Po
//if(count>4) .ml\z5
// siteStop(); KsE$^`
} oe2*$\?.
u_ l?d
/.CS6W^z
System.err.println("文件下载结束！"); %=9o'Y,4
} Z|Rc54Ct
catch(Exception e){e.printStackTrace ();} @KU;'th
} 1zH?.-
'N+;{8C-{
W&R67ff|
//获得文件长度 @48!e-W
public long getFileSize() R6oD
{ KCw
int nFileLength = -1; QOYMT(j
try{ 2w8cJadT'p
URL url = new URL(siteInfoBean.getSSiteURL()); w43b=7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4:NMZ `~
httpConnection.setRequestProperty("User-Agent","NetFox"); ^Cp2#d*
N\B&|;-V
h ~yTkN]
int responseCode=httpConnection.getResponseCode(); #)xlBq4cZ
if(responseCode>=400) 8tQL$CbO
{ <nD@4J-A0
processErrorCode(responseCode); [~ 2m*Q
return -2; //-2 represent access is error :??W3ROn
} #&?ER]|3
-d#08\
[r8[lkR
String sHeader; {.AN4
;hO6 p
_.V5-iN
for(int i=1;;i++) ~5%3]
{ JZ`h+fAt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); g=Xy{Vm
//Utility.log(in.readLine()); UCfouQCj
sHeader=httpConnection.getHeaderFieldKey(i); W}TP(~x'N
if(sHeader!=null) (?R!y -
{ M(K7xx+G
if(sHeader.equals("Content-Length")) .\ fpjQW
{ ?{aJ#w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); rC_1f3A
break; pgh(~[
} K;sC#9m
} SsW<,T
else Aipm=C8
break; cxSHSv1;
} I8)D
} {m~)~/z?
catch(IOException e){e.printStackTrace ();} #2ta8m),
catch(Exception e){e.printStackTrace ();} MooH`2Fd
6A]I" E]5
6P717[
Utility.log(nFileLength); DMG'8\5C
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4xbWDu]
return nFileLength; =dA]nM
} -i{_$G8W/c
#UL75
>wmHCOL:
//保存下载信息（文件指针位置） C 4C/
private void write_nPos() ^U5N!"6R
{ i56Rdb
try{ FsWp>}o
output = new DataOutputStream(new FileOutputStream(tmpFile)); WVpx
output.writeInt(nStartPos.length); Oj_]`
for(int i=0;i<nStartPos.length;i++) qna!j|90Lp
{ )M+po-6$1
// output.writeLong(nPos); {!wW,3|Pu
output.writeLong(fileSplitterFetch.nStartPos); HYGd :SeH
output.writeLong(fileSplitterFetch.nEndPos); p:y\{k"
} =O0A(ca"g
output.close(); Vlz\n
} Lg!E
catch(IOException e){e.printStackTrace ();} K=0xR*ll5
catch(Exception e){e.printStackTrace ();} 4sQm"XgE
} :FS5BT$=
b7\>=
fb`x1Q
//读取保存的下载信息（文件指针位置） c:.5@eq^
private void read_nPos() "kFH*I+v
{ pIC'nO_
try{ +vxf_*0;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \)t//0
int nCount = input.readInt(); d;l%XZe
nStartPos = new long[nCount]; sGhw23
nEndPos = new long[nCount]; !nkIXgWz
for(int i=0;i<nStartPos.length;i++) r/AOgS
{ ^0|:
nStartPos = input.readLong(); i'H]N8,A
nEndPos = input.readLong(); F}45.CrD
} gdTW ~b
input.close(); ]R)wBug
} ZwsQ}5
catch(IOException e){e.printStackTrace ();} `9[n5-t
catch(Exception e){e.printStackTrace ();} B3&C&o.h
} ddKP3}
BT8)t.+pv
:s_.K'4?a
private void processErrorCode(int nErrorCode) : H;S"D
{ Ot-P J i
System.err.println("Error Code : " + nErrorCode); {Dl@/fz
} z;oia!9z
TIiYic!_~
\MRd4vufv
//停止文件下载 oc] C+l
public void siteStop() Ds"%=
{ _ncBq;j{
bStop = true; DKfpap}8u
for(int i=0;i<nStartPos.length;i++) VNT?
fileSplitterFetch.splitterStop(); WM|G/'q
fTPm Fb
iZfZF
} Sdmz(R
} PjBAf'
//负责部分文件的抓取 ,v})
**FileSplitterFetch.java q&>fKSnKs
*/ 1O0. CC,p
package NetFox; G) KI{D
hmkb!)
ZKEoU!
import java.io.*; 2! ,ndLA
import java.net.*; 9Jh&C5\\
0~BaQ, A@
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public class FileSplitterFetch extends Thread { ?sdSi--
tDL.+6/
fK=0?]s}I
String sURL; //File URL qypF}Pw
long nStartPos; //File Snippet Start Position *s 4Ym
long nEndPos; //File Snippet End Position I ]o|mjvs
int nThreadID; //Thread's ID Q]TZyk
boolean bDownOver = false; //Downing is over tKUW
boolean bStop = false; //Stop identical yW'{Z]09
FileAccessI fileAccessI = null; //File Access interface [Lje?M* r
L:Rg3eo
+8Q @R)3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException CtN\-E-
{ wg)Bx#>\L:
this.sURL = sURL; B/a`5&G]
this.nStartPos = nStart; Xykoq"dbb
this.nEndPos = nEnd; ^"|q~2
nThreadID = id; Ey:?!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "Y:>^F;
} &Wa3/mWK
azIhp{rHw
i@rUZYF
public void run() l#v52
{ z{ eZsh b
while(nStartPos < nEndPos && !bStop) jSvq1$U
{ J#Y0R"fo
$*X?]?
DjK7_'7(L
try{ :l]qTCmY
URL url = new URL(sURL); n.9k5r@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g`'!Vgd?M[
httpConnection.setRequestProperty("User-Agent","NetFox"); Brs6RkRf
String sProperty = "bytes="+nStartPos+"-"; ~fD\=- S1
httpConnection.setRequestProperty("RANGE",sProperty); DTA$,1JuD
Utility.log(sProperty); x f{`uHa8
9O&gR46.
R[\1Kk(Zo
InputStream input = httpConnection.getInputStream(); ylczM^@
//logResponseHead(httpConnection); Q]=/e7
\='LR!_
JL#LCU ?
byte[] b = new byte[1024]; 6 M:?W"
int nRead; 1SS1P0Ur
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6;Z`9PGp
{ YJ,"@n_
nStartPos += fileAccessI.write(b,0,nRead); iNkN'("
//if(nThreadID == 1) ~ e?af
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); QlB9m2XB
} )=gU~UV
*ilVkV"U
q)?!]|pZ
Utility.log("Thread " + nThreadID + " is over!"); }[|9vF"g.y
bDownOver = true; [g}#R#Y)
//nPos = fileAccessI.write (b,0,nRead); vde!k_,wZ
} ^"I@ 8k
catch(Exception e){e.printStackTrace ();} w+')wyB
} YBj*c$.D0
} yI|x 5f
F;`c0ja]
HFjSM~
//打印回应的头信息 8*b{8%<K
public void logResponseHead(HttpURLConnection con) T&/n.-@nk
{ cz/E
for(int i=1;;i++) fCNQUK{Gs5
{ e}{#VB<
String header=con.getHeaderFieldKey(i); 9C?SEbC
if(header!=null) b4^O=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |H5GWZ O{^
Utility.log(header+" : "+con.getHeaderField(header)); a8)2I~j
else ]Zh$9YK
break; M __S)
} FsOJmWZ
} w3 vZ}1|
1l)j(,Zd*
7&P70DO
public void splitterStop() pFMjfWD,C
{ NL|c5y<r
bStop = true; 7P2(q
} 71E~~$
0s//&'*Q
$'>iNMtK{p
} .?APDr"QQH
\6 JY#%
<tZtt9j_
/* ?m5"|f\
**FileAccess.java 'z}9BGR!
*//文件访问(定位，写) ZaaBg
package NetFox; 4w9=z,
import java.io.*; d5LBL'/o
6v scu2
_0u=}tc
public class FileAccessI implements Serializable{ E|-5=!]fX
nnBS;5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hFycSu
RandomAccessFile oSavedFile; ~~&Bp_9QXN
long nPos; $D65&R
=os!^{p7>
JDa_;bqL
public FileAccessI() throws IOException POl-S<QV
{ E[ -yfP~[
this("",0); C%<Dq0j
} ( -q0!]E
$tW E9_
%}N01P|X>
public FileAccessI(String sName,long nPos) throws IOException y"Fu=
{ _?felxG[
oSavedFile = new RandomAccessFile(sName,"rw"); %LHt{:9.
this.nPos = nPos; njJTEUd">
oSavedFile.seek(nPos); 7Cz=;
} d^~yUk
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h*<`ct xL
public synchronized int write(byte[] b,int nStart,int nLen) v0&DD&mp
{ :0%[u(
int n = -1; dj] O
try{ ^Ar1V!PFk
oSavedFile.write(b,nStart,nLen); .i )K#82
n = nLen; u&={hJ&7
} >_]Ov:5
catch(IOException e) # ^,8JRA
{ /8:e| ]
e.printStackTrace (); ,'YKL",
} nzAySMD_
{_4Hsw?s6
s H'FqV,)
return n; 8*m,#
} z\, lPwB2
! B`
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} hqHk,#
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V1nqEdhk
/* &q-P O
**SiteInfoBean.java ,=@WE>ip
*/ d8 v9[4
package NetFox; V$$9Rh
79 _8Oh
AYoTCi%7E
public class SiteInfoBean { "\~>[on
M`=\ijUwN
g=v'[JPd
private String sSiteURL; //Site's URL &,Rye Q
private String sFilePath; //Saved File's Path 7?_gm>]a
private String sFileName; //Saved File's Name k&K'FaM!
private int nSplitter; //Count of Splited Downloading File {<Y!'WL{
1 Cz}|#U
eUu<q/FUMj
public SiteInfoBean() ~(c<M>Q8
{//nSplitter的缺省值为5 :SMf (E 5
//default value of nSplitter is 5 1z,P"?Q
this("","","",5); O]="ggq&
} =NK'xPr
&jnBDr
P()&?C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rnMi >?
{ )`|`PB
sSiteURL= sURL; /a}N6KUi
sFilePath = sPath; Zl!
sFileName = sName; #QOb[9(Tu(
this.nSplitter = nSpiltter; d[;&2Jz*
%[L/JJbP&Z
&R<K>i
} HDE5Mg "
]d|M@v~c4
*ZRk)
public String getSSiteURL() 6khm@}}
{ W8]?dL}|
return sSiteURL; Qe9}%k6@E
} uE,TEa9;
^MhMYA
B/~ubw
public void setSSiteURL(String value) Gh3f^PWnc
{ $b_~
sSiteURL = value; 7Y4D9pw
} Csgby(D*O
=@P(cFJ/
8JMxA2tZhG
public String getSFilePath() n-wOLH
{ H\<PGC"_Y
return sFilePath; |`I9K#w3
} }U%E-:
-=u9>S)!c
#H8QX5b)
public void setSFilePath(String value) YAi@EvzCVy
{ 9(a*0H
sFilePath = value; Q"LlBp>t|#
} _$}@hD*R~
0@&;JMh6<
^d9o \
public String getSFileName() ^@'zQa
{ [[4!b E
return sFileName; 3)^2X
} zJ8jJFL+Y
S~g"
$qoal
public void setSFileName(String value) Y\(?&7Aax
{ puF*WxU)
sFileName = value; #Oa`P
} h9. Yux
Sn;q:e3i{A
nu16L$]
public int getNSplitter() P^BSl7cT
{ 3[kl` *`
return nSplitter; ZGd7e.u=
} #g Rns
yzGBGC
Zc9S[ivq
public void setNSplitter(int nCount) eQ#"-i
{ LXc;`]
nSplitter = nCount; _UF'Cf+Y
} kRiZ6mn
} Ao9|t;i
T(kG"dz
p|)j{nc
/* gF~ }
**Utility.java 0}Qd
*/ fAT M?
package NetFox; |'L$ogt6
'EU|w,GL}
8PRB_ny
public class Utility { 5XNFu C9E
m?1AgsBR
uKT\\1Jrq
public Utility() {~=gKZ:-@
{ D rouEm
yyjgPbLN=
61z^(F$@
} z8PV&o
W%#LHluP
//线程睡眠 Y;sN UX
public static void sleep(int nSecond) ,fs>+]UY3
{ \mwxV!!b$
try{ !h*F58
Thread.sleep(nSecond); wA%,_s/U
} dM5N1$1,
catch(Exception e) QnH~' k
{ I9cZZ`vs
e.printStackTrace (); ~0{F,R.$
} m8v=pab e
} :\#/T,K"
]=5D98B
//日志 ~uO9>(?D
public static void log(String sMsg) m\|ie8
{ RLF]Wa,
System.err.println(sMsg); -s6;IoG/
} Rd+`b
>!P !F(
"Ze<dB#,Y
public static void log(int sMsg) _ 3jY,*
{ `vrLFPdO
System.err.println(sMsg); % wh>_Ho
} ?OWJUmQ
} TSP#.QY
|?uUw$oh
X>rv{@KbL
/* K1fnHpK
**TestMethod.java qH*Fv:qnM
*/ ^:m7Qd?Z[
package NetFox; \;Q:a /ur9
#mcGT\tQ
q6N6QI8/
public class TestMethod { 'Y-Y By :
2NqO,B|R
pGSS
public TestMethod() iED gcg7
{ ///xx/weblogic60b2_win.exe " [K>faV
try{ 'sTMUPg`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G9a6 $K)b
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); {rZ )!
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4VfZw\^
fileFetch.start(); 25jgM!QBXF
} X\LiV{c
catch(Exception e){e.printStackTrace ();} | D,->k
i}e OWi
x-=qlg&EI
} dy2<b+..
8 gzf$Oc
p EbyQ[
public static void main(String[] args) S9S%7pE
{ xy1R_*.F^T
new TestMethod(); y[sO0u\
} 8Ir = @
} [cf!%3>53
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