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)); ATR!7i\|
} +wkjS r`e
for(int i=0;i<nEndPos.length-1;i++) YfRkwKjy(
{ /{|fyKo\?
nEndPos = nStartPos[i+1]; P3oI2\)*i
} R+Y4|
nEndPos[nEndPos.length-1] = nFileLength; %rxO_
} H/Llj.-jg
} up'Tit
);FJx~b
vsa92c@T
//启动子线程 +Z85HY{
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [o?*"c
for(int i=0;i<nStartPos.length;i++) p1vp8p
{ :H c0b=
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u;`U*@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), /tUy3myJ
nStartPos,nEndPos,i); i\dc>C ;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /c,(8{(O
fileSplitterFetch.start(); lg(bDKm
} Dq)j:f#QM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), z`\F@pX%wC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); e6!LSx}y
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tzs</2 G,
nEndPos = " + nFileLength); yV"ZRrjO'Z
// fileSplitterFetch[nPos.length-1].start(); *W kIq>
f"St&q>[s
V =-WYu
//等待子线程结束 aJcf`<p
//int count = 0; 95z]9UL
//是否结束while循环 ca>Z7qT!
boolean breakWhile = false; 0X^Ke(/89
;g~TWy^o
sq;s]@~
while(!bStop) ~j<+k4I~
{ 3"P }n
write_nPos(); Yh>]-SCw
Utility.sleep(500); 1CHeufQ
breakWhile = true; Ry|!pV
8KRba4[
f/V 2f].
for(int i=0;i<nStartPos.length;i++) ldp%{"ZZ
{ L@gWzC~?Q
if(!fileSplitterFetch.bDownOver) LU9A#
{ "70WUx(\t
breakWhile = false; G8;w{-{m
break; S*n@81Z
} *f?4
} ="g*\s?r
if(breakWhile) K#U<ib-v
break; T8HF|%I
|<GDUwC_;
VP6ZiQ|
//count++; yUp,NfS]o
//if(count>4) nH<eR)0
// siteStop(); 'z[Sp~I\
} SGe^ogO"v
g]c6&Y,#
{\(L%\sV@
System.err.println("文件下载结束！"); ]GRWnif
} 3.qTLga|}
catch(Exception e){e.printStackTrace ();} lgb?)=
} q5#J~n8Wr
y>aZXa
tuhA 9}E
//获得文件长度 M`l.t -ut
public long getFileSize() *q1%IJ
{ >>5NX"{
int nFileLength = -1; ;W^o@*i{>
try{ (t4&,W_spA
URL url = new URL(siteInfoBean.getSSiteURL()); +9")KQT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >2Kh0rIH
httpConnection.setRequestProperty("User-Agent","NetFox"); 7bV{Q355P
/;utcc
a(0*um(
int responseCode=httpConnection.getResponseCode(); 9J?wO9rI
if(responseCode>=400) iURk=*Z=
{ E~_]Lfs)
processErrorCode(responseCode); E8~}PQW:I
return -2; //-2 represent access is error 8f3vjK'
} YWxc-fPZ
UNkCL4N
/>9OR
String sHeader; lHhUC16>
u,w:SM@*(
`4~H/'%QB
for(int i=1;;i++) .;*s`t
{ - h9?1vc7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); oD$J0{K6
//Utility.log(in.readLine()); >`%'4<I
sHeader=httpConnection.getHeaderFieldKey(i); J;f!!<l\
if(sHeader!=null) ,Bal
{ )-`;1ca)s
if(sHeader.equals("Content-Length")) >J>b>SU=-
{ f?'JAC*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); k+DR]icv
break; 'FS?a
} gR}35:$Z-
} 1)[]x9]^q'
else PgRDKygE
break; &T}''
} Y14W?|KOB
} H(&4[%;MP
catch(IOException e){e.printStackTrace ();} T9879[ZU\
catch(Exception e){e.printStackTrace ();} ''Cay0h
,qYJioWX
>z.<u|r2
Utility.log(nFileLength); ?|ZTaX6A
Ed ,D8ND
4M^G`WA}t9
return nFileLength; 1 %,a =,v
} b/Xbs0q
MC{ 2X
44F`$.v96
//保存下载信息（文件指针位置） ]| +<P-
private void write_nPos() 91xB9k1zO
{ qvv2O1c"A
try{ ;j)FnY=:-
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?2g`8[">
output.writeInt(nStartPos.length); C|o`k9I#
for(int i=0;i<nStartPos.length;i++) tT79p.z B
{ w#g#8o>'
// output.writeLong(nPos); P';?YV0
output.writeLong(fileSplitterFetch.nStartPos); @, Wvvh
output.writeLong(fileSplitterFetch.nEndPos); jvQ*t_L
} H8'Z#"h
output.close(); zD?K>I=
} Iy6$7~
catch(IOException e){e.printStackTrace ();} l}lIi8
catch(Exception e){e.printStackTrace ();} w&%~3Cz.
} Y}vr>\
E{n:J3_X^d
4NdN<#Lr
//读取保存的下载信息（文件指针位置） nM0[P6p
private void read_nPos() [u._q:A
{ u@4V7;L
try{ zrU{@z$l
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Usta0Ag
int nCount = input.readInt(); uZ=NSbYsA
nStartPos = new long[nCount]; *tAg*$
nEndPos = new long[nCount]; gc?#pP
for(int i=0;i<nStartPos.length;i++) 3dDX8M?
{ "hdvHUz
nStartPos = input.readLong(); ~wVd$%7`
nEndPos = input.readLong(); %zOh
} d%0~c'D8a
input.close(); Ogp"u b8
} \~5C7^_
catch(IOException e){e.printStackTrace ();} YLVPAODY
catch(Exception e){e.printStackTrace ();} Y9`5G%
} A|@_}h"WG
d` [HT``
gy;+_'.j
private void processErrorCode(int nErrorCode) :Pv*,qHE
{ /AQMFx4-5
System.err.println("Error Code : " + nErrorCode); oy;K_9\
} ru7RcYRq
Dxk+P!!K
1\r|g2Z :
//停止文件下载 =ID 2
public void siteStop() >X51$wBL
{ %b^OeWip
bStop = true; BY]i;GVq
for(int i=0;i<nStartPos.length;i++) np4+"
fileSplitterFetch.splitterStop(); =?-ye!w
IO/4.m-aN#
YOJ6w
} x1BobhU~Zl
} [S@}T zE
//负责部分文件的抓取 0{j&6I2
**FileSplitterFetch.java "t0kAG
*/ yA3wtm/?
package NetFox; 8Y#\xzod
"{D|@Bc
h48SItY
import java.io.*; >pr=|$zk=
import java.net.*; 36n>jS&
X~xd/M=9^
`w.AQ?p@
public class FileSplitterFetch extends Thread { {Ixg2=E\
SKW%X8
L-9~uM3@\
String sURL; //File URL Kb^>-[Yx
long nStartPos; //File Snippet Start Position >[1W:KQA
long nEndPos; //File Snippet End Position ZlojbL@|4
int nThreadID; //Thread's ID EutP\K_Y
boolean bDownOver = false; //Downing is over \t|M-%&)4
boolean bStop = false; //Stop identical -!8(bjlJ&
FileAccessI fileAccessI = null; //File Access interface _A~4NW{U7
:#lIx%l
${8?N:>t
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4Ua>Yw0
{ @+WQ ^
this.sURL = sURL; ehA;i.n
this.nStartPos = nStart; +L=*:e\j
this.nEndPos = nEnd; n\ Hs@.
nThreadID = id; >~\89E02
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |0,vQv
} dCFlM&(i
;zdxs'hJ
>dM8aJzC
public void run() K2<~(78C
{ z~\t|Z]G,|
while(nStartPos < nEndPos && !bStop) l)-Mq@V
{ @K:N,@yq
w;e(Gb%9
uZi.HG{<)
try{ &,.Y9; b
URL url = new URL(sURL); P%MfCpyj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3! ~K^Z]
httpConnection.setRequestProperty("User-Agent","NetFox"); {W\T"7H
String sProperty = "bytes="+nStartPos+"-"; $@i"un;
httpConnection.setRequestProperty("RANGE",sProperty); _pH{yhA
Utility.log(sProperty); [0UGuj
]p!Gt,rYq
-TV?E%r
InputStream input = httpConnection.getInputStream(); cc44R|Kr$$
//logResponseHead(httpConnection); |0z;K:5s
Ap$y%6
> MG>=A
byte[] b = new byte[1024]; UgN28YrW
int nRead; 5%}wV,Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j:bgR8%e
{ mw^7oO#
nStartPos += fileAccessI.write(b,0,nRead); qSx(X!YS
//if(nThreadID == 1) |/ }\6L]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); y3<Y?M4
} 1h7+@#<:a
<*EZ@XoN>
n$(p-po
Utility.log("Thread " + nThreadID + " is over!"); b|5w]<?'
bDownOver = true; Xes|[*Y!V
//nPos = fileAccessI.write (b,0,nRead); |7@O($b
} -xD*tf*
catch(Exception e){e.printStackTrace ();} aV1lJ;0
} Hk7K`9
} ,pBh`av
T$=4O9G
Q7bq
//打印回应的头信息 BN,>&1I
public void logResponseHead(HttpURLConnection con) lHB) b}7E
{ [ REf>_R
for(int i=1;;i++) C}5M;|%3)
{ u? fTL2~
String header=con.getHeaderFieldKey(i); #?B%Ja% ;W
if(header!=null) 1=2^90
//responseHeaders.put(header,httpConnection.getHeaderField(header)); u z\0cX_
Utility.log(header+" : "+con.getHeaderField(header)); q/1Or;iK
else z}Jr^>
break; CCDDK L]N:
} 4ujvD^
} t_ur&.^SB
MP>n)!R[`
e&9F\e
public void splitterStop() @uH#qg7
{ =iHiPvP0
bStop = true; Fd\e*ww'
} A4mSJ6K]
>\A8#@1
k#:2'!7G
} (5$ZvXx?}
AD('=g J
/( 6|{B
/* W >(vYU
**FileAccess.java j*;N\;iL!*
*//文件访问(定位，写) EN!?:RV
package NetFox; !8tS|C#2
import java.io.*; insY(.N
u2(eaP8d
4O{Avt7C
public class FileAccessI implements Serializable{ =wq;@'U
r(2R<A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 'PWQnt_U
RandomAccessFile oSavedFile; C0x"pO7
long nPos; /OGA$eP
9x`4RE
!Ngw\@f
public FileAccessI() throws IOException KbxR Lx]w
{ 34|a:5c
this("",0); AN9[G
} 5c-N0@\
Me:{{-V4
?PPZp6A3L=
public FileAccessI(String sName,long nPos) throws IOException v@EQ^C2.&
{ yy(A(}
oSavedFile = new RandomAccessFile(sName,"rw"); bb=uF1
this.nPos = nPos; F#+.>!
oSavedFile.seek(nPos); X21dX`eMN
} 84&XW
}{],GHCjQ
G\iyJSj[P
public synchronized int write(byte[] b,int nStart,int nLen) G{ mC7@
{ v vE\
int n = -1; `3iQZui
try{ ?n'OFpd
oSavedFile.write(b,nStart,nLen); %kU'hzLg
n = nLen; q9}m!*8e
} eK`PxoTI-I
catch(IOException e) ,|To#umym>
{ .\5$MIF
e.printStackTrace (); S-Ai3)t6
} I+,SZ]n
$EBb"+Y'T
Jfg7\&|
return n; NO>k
} ]7qiUdxt:
ms~8QL
'dt\db5p
} mrZ`Lm#>pS
,-rB=|w
]HvZ$
/* r[HT9
**SiteInfoBean.java w+f=RHX"{
*/ G?V"SU.
package NetFox; QD<eQsvV
jQtSwVDr
:%tuNJjj
public class SiteInfoBean { F,v7ifo#f
Bh`IXu
R,Ml&4pZ}
private String sSiteURL; //Site's URL if~rp-\P
private String sFilePath; //Saved File's Path XT||M)#
private String sFileName; //Saved File's Name j Selop>N
private int nSplitter; //Count of Splited Downloading File qa!RH]B3
dbO#
YBSl-G'
public SiteInfoBean() Jgi Iq
{//nSplitter的缺省值为5 (@]tG?I=
//default value of nSplitter is 5 H=.K
this("","","",5); Hq xK\m%,.
} *W^=XbG
:)P<jX-G
,$Tk$
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =s[&;B`s
{ \p6 }
sSiteURL= sURL; jp m#hH{R
sFilePath = sPath; |NEd@
sFileName = sName; Bxv8RB
this.nSplitter = nSpiltter; H~m]nV,r
#AncOo
zrx JN
} *]{=8zc2
EUwQIA2c8N
r'd/qnd
public String getSSiteURL() }[,3yfiX
{ *ro.mQ_
return sSiteURL; ){tPP$-i=
} \GHOg.P
K^ 6+Ily
;E's4jWq
public void setSSiteURL(String value) _0]QS4a][c
{ uL>:tb
sSiteURL = value; [.U^Wrd
} 6_ ]8\n
^/{4'\p
aQh?}=da
public String getSFilePath() l;5`0N?QO
{ Uh\]?G[G
return sFilePath; <bX 1,}?
} n2E4!L|q
MF|*AB|E
%O/d4
public void setSFilePath(String value) 5&qY3@I7l
{ #PH#2/[
sFilePath = value; ]BfR.,,
} {_as!5l
b_ JWnh
I{<;;;a
public String getSFileName() F '#^`G9
{ vXf:~G]
return sFileName; (txt8q
} i+RD]QL
'Q`C[*c
^;64!BaK
public void setSFileName(String value) h60\ Y 8
{ -eq=4N=s
sFileName = value; uWrFunh%
} }s6G!v^2""
p5`ZyD]+
+3HPA#A
public int getNSplitter() Gt5$6>A
{ @tQ2E}psP,
return nSplitter; +_-Y`O!Q
} b_mWu@$
2*YP"Ryh
:}y| 4*z
public void setNSplitter(int nCount) {9'hOi50
{ :f]!O@.~
nSplitter = nCount; 7%YYr^d
} kc|>Q7~{
} QqjTLuN
:o<N!*pT
L"9 Gc
/* I1~G$)w#
**Utility.java %Il;B~t
*/ tgfM:kzw
package NetFox; {a@hRY_
$~TfL{$
`~|DoSi^d
public class Utility { Es~DHX
>&[3
>eu `!8
public Utility() 8k%H[Smn:
{ Yd.027
X-v~o/r7
^^'[%ok
} sxt`0oE
R;.d/U|av
//线程睡眠 9g4QVo|
public static void sleep(int nSecond) jvWI_Fto
{ 7Qt2gf
try{ /Q]:Uf.J
Thread.sleep(nSecond); GP Ix@k
} tgK x4
catch(Exception e) +RdI;QmM
{ -t%L#1k
e.printStackTrace (); CR.bMF}
} `M,Nd'5&|
} xV?*!m$V%R
z6Fun
//日志 yX3PUO9
public static void log(String sMsg) phe"JNML
{ IF& PGo
System.err.println(sMsg); G1p43
} *|@+rbjVC
wd"TM
bD d_}
public static void log(int sMsg) Plb}dID"
{ DqRLx85d1
System.err.println(sMsg); /!:L7@BZ
} 6/VNuQ_#
} rXlx?GV
{ _-wG3f|
~.iA`${y%
/* HqB|SWyK
**TestMethod.java VVgsLQd
*/ yW[L,N7d
package NetFox; Jm%mm SYK
ofVEao
8g-P_[>
public class TestMethod { dG"K/|
$R8>u#K!
<&KLo>B^
public TestMethod() /cM 5
{ ///xx/weblogic60b2_win.exe ^zKt{a
try{ a4Ls^
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); bx;yHIRb
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ?VUgwP_=
SiteFileFetch fileFetch = new SiteFileFetch(bean); >7"$}5d
fileFetch.start(); "^Y6ctw
} }7-7t{G
catch(Exception e){e.printStackTrace ();} `Fz\wPd
&3jBE--
Lf[G>0t&n
} ]sf2"~v
zoJ_=- *s
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public static void main(String[] args) };i&a%I|
{ MJy;GzJ O
new TestMethod(); F\zkyk4
} xq#U4E
} <'yf|N!9G
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