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)); ~<O,Vs_C/
} ^#SBpLw
for(int i=0;i<nEndPos.length-1;i++) zy)i1d
{ _wu*M
nEndPos = nStartPos[i+1]; PdE>@0X?M
} 7'j9rmTXs
nEndPos[nEndPos.length-1] = nFileLength; Mtp%co)f
} esq<xuZM4
} 6Z c)0I'
#x)}29%e#
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//启动子线程 $h[Yzl
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; j$PI,`
for(int i=0;i<nStartPos.length;i++) $WaZ_kt
{ $I8[BYblB
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rg)h5G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h}6_ybmZ
nStartPos,nEndPos,i); tgN92Q.i6T
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #5{sglC"|F
fileSplitterFetch.start(); j%xBo:
} YmDn+VIg
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H@W0gK(cS;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); V5s&hZZYa
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *{[d%B<lp
nEndPos = " + nFileLength); P\(30
// fileSplitterFetch[nPos.length-1].start(); LknVqZ|k
rm|7 [mK
%V_eJC""?
//等待子线程结束 mw+j|{[
//int count = 0; jT^!J+?6K+
//是否结束while循环 0xP:9rm
boolean breakWhile = false; fN[n>%)VO<
{j@+h%sF>+
9ECS,r*B
while(!bStop) jsm0kz
{ _S5gcPcF"
write_nPos(); V/-MIH7SF
Utility.sleep(500); -1mvhR~
breakWhile = true; d}% (jJ(I
w2Kq(^?
lU$X4JBzS
for(int i=0;i<nStartPos.length;i++) [4gjC
{ IwRQL%
if(!fileSplitterFetch.bDownOver) BE4\U_]a3
{ NbDda/7ki
breakWhile = false; uBRw>"c_*8
break; 6Ct0hk4
} C'<'7g4
} _3&/(B%H
if(breakWhile) A$m<@%Sz
break; m/?h2McS
gz\j('~-D
8p,>y(o
//count++; B1,?{Ur
//if(count>4) 32y[
// siteStop(); M,G8*HI"
} `,-STIh)
Oga1u
,\>g
System.err.println("文件下载结束！"); n)CH^WHL&
} 88YC0!Ni
catch(Exception e){e.printStackTrace ();} 'FxYMSZS$
} m)k-uWc$C
I}%mfojC
$Sw,hb
//获得文件长度 T#N80BH[
public long getFileSize() F*!gzKZ"
{ \7DCwu[0M
int nFileLength = -1; gix>DHq$k
try{ Xj;2h{#s
URL url = new URL(siteInfoBean.getSSiteURL()); +gNX7xuY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )|:8zDuJ
httpConnection.setRequestProperty("User-Agent","NetFox"); &<t79d%{
3Tw%W0q
S5/p=H:
int responseCode=httpConnection.getResponseCode(); Bxt_a.LthH
if(responseCode>=400) ]:!8 s\#
{ k!vHO
processErrorCode(responseCode); QRiF!D)Nk
return -2; //-2 represent access is error 5iv@@1c
} `.`FgaJ |
4K'|DO|dH
e sGlMq
String sHeader; oFn4%S:
n4R]+&*
b<\GI7
for(int i=1;;i++) M;PlSb
{ QU%N*bFW%P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ks51:M
//Utility.log(in.readLine()); #'KY`&Tw&
sHeader=httpConnection.getHeaderFieldKey(i); Tz2x9b\82
if(sHeader!=null) 1sMV`qv>
{ !,R
if(sHeader.equals("Content-Length")) ]%||KC!O
{ \`&xprqAw
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %cd]xQpCp
break; Ltl]j*yei
} _rG-#BKW8L
} IY~ {)X
else $Uy#/MX
break; Sn0Xl3yr
} sB8p( L
} ID+,[TM`
catch(IOException e){e.printStackTrace ();} W=F3XYS
catch(Exception e){e.printStackTrace ();} -$b?rt]h1g
sq48#5Tc^r
~{9x6<g!
Utility.log(nFileLength); R rxRa[{Z
C~:b*X
7Z VVR*n|
return nFileLength; 4fD`M(wv
} "wF*O"WQo
C\J@fpH(t`
#'#4hJ*YC
//保存下载信息（文件指针位置） Dn: Yi8=
private void write_nPos() VDPxue
{ H]U"+52h
try{ $=7H1 w
output = new DataOutputStream(new FileOutputStream(tmpFile)); j#CuR7m
output.writeInt(nStartPos.length); ZIDFF
for(int i=0;i<nStartPos.length;i++) D. 77WjwQ
{ F6~b#Jz&i
// output.writeLong(nPos); 7Y4%R`9H
output.writeLong(fileSplitterFetch.nStartPos); p-a]"l+L
output.writeLong(fileSplitterFetch.nEndPos); KqFmFcf|
} _AVy:~/
output.close(); RLv&,$$0
} rnJS[o0
catch(IOException e){e.printStackTrace ();} 7%W!k zp>
catch(Exception e){e.printStackTrace ();} zkH<aLRB
} EWSr@}2j .
{6ajsy5=
9'D8[p%
//读取保存的下载信息（文件指针位置） 0H;"5
private void read_nPos() R,uJK)m
{ oJhEHx[f
try{ hcj{%^p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _Wq7U1v`
int nCount = input.readInt(); 4;08n|C
nStartPos = new long[nCount]; kg zwlKK
nEndPos = new long[nCount]; CzK%x?~]
for(int i=0;i<nStartPos.length;i++) K@I+]5E%?
{ X5|?/aR}
nStartPos = input.readLong(); n(9F:N
nEndPos = input.readLong(); Lqg7D\7j
} l)|z2H
input.close(); !d/`[9jY
} W=q?tD~V
catch(IOException e){e.printStackTrace ();} 7l[t9ON
catch(Exception e){e.printStackTrace ();} 4U_rB9K$
} o-~-F+mj#
}ZxW"5oq
jc3ExOH
private void processErrorCode(int nErrorCode) rHH#@Zx
{ rD_Ss.\^g
System.err.println("Error Code : " + nErrorCode); ~4l6unCI
} "X\q%%P=?
=B1`R%t
T@2f&Un^
//停止文件下载 /M5=tW#e
public void siteStop() cKaL K#~
{ h]G6~TYI5
bStop = true; =9#i<te
for(int i=0;i<nStartPos.length;i++) ':5U&
fileSplitterFetch.splitterStop(); fJ,8g/f8
wCqE4i
\UVT_=Y
} Q&\ZC?y4
} <e@I1iL37y
//负责部分文件的抓取 Lx|w~+k}
**FileSplitterFetch.java 2n<qAl$t
*/ "i;*\+x
package NetFox; 18l~4"|fk
H{p[Ghp
Zb5T90s%
import java.io.*; T1Ln)CS?9
import java.net.*; #l8K8GLuf
D| 3AjzW
Ip1QVND
public class FileSplitterFetch extends Thread { bYRQI=gW':
L>|A6S#y8/
@pyA;>U
String sURL; //File URL B)LXxdkOn
long nStartPos; //File Snippet Start Position ^^U)WB
long nEndPos; //File Snippet End Position < :S?t2C
int nThreadID; //Thread's ID |wl")|b%
boolean bDownOver = false; //Downing is over TU^tW
boolean bStop = false; //Stop identical CVn;RF6
FileAccessI fileAccessI = null; //File Access interface 4.$hHFqS^5
5wVi{P5+
la6e`
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mAtG&my)
{ J@&$U7t
this.sURL = sURL; G!fE'B
this.nStartPos = nStart; )xXrs^
this.nEndPos = nEnd; MzA
nThreadID = id; X]f#w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "1\RdTw
} 4%Wn}@
&vGEz*F
3vEjf
public void run() !3gpiQH{
{ wLg:YM"
while(nStartPos < nEndPos && !bStop) YQw/[
{ Ii2g+SlQDa
m/"=5*pA
_<&K]e@dp
try{ -t706(#k
URL url = new URL(sURL); ~`Gcq"7,!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); m$G?e9{
httpConnection.setRequestProperty("User-Agent","NetFox"); 2v; 7ohK
String sProperty = "bytes="+nStartPos+"-"; D=Yag!1
httpConnection.setRequestProperty("RANGE",sProperty); Y_TL4
Utility.log(sProperty); ^5iY/t~Q
IDVY2`sM
;gw!;!T
InputStream input = httpConnection.getInputStream(); f%{ ag
//logResponseHead(httpConnection); WG!;,~f>o
Tef3 Z6
^?l-YnQqm?
byte[] b = new byte[1024]; "=0lcbC
int nRead; j,V$vKP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) lyc{Z%!3
{ E6d8z=X(
nStartPos += fileAccessI.write(b,0,nRead); ^#6%*(D
//if(nThreadID == 1) =Z$=-\<x0.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); kA9 X!)2w
} \Q BpgMi(
g{f>jd
[OToz~=)
Utility.log("Thread " + nThreadID + " is over!"); HZ`G)1&)
bDownOver = true; 5 <>agK]
//nPos = fileAccessI.write (b,0,nRead); gpTF^.(
} "vHAp55B{
catch(Exception e){e.printStackTrace ();} W YqL
} M`,Z#)Af
} ,,-[P*@
28L'7
%l$&_xV-
//打印回应的头信息 (YWc%f4
public void logResponseHead(HttpURLConnection con) -X[8soz
{ R5~vmT5W
for(int i=1;;i++) ;ZW}47:BS6
{ >[3,qP]E
String header=con.getHeaderFieldKey(i); 88LbO(q\d
if(header!=null) OgpH{"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); =D:R'0YH
Utility.log(header+" : "+con.getHeaderField(header)); as47eZ0\
else #K~j9DuR
break; IgnY*2FT
} \/dm}' `
} ur quVb
&+|4(d1
>"My\o
public void splitterStop() j`&i4K:
{ ^Ypx|-Vu!
bStop = true; +53zI|I
} H\>I&gC'
[LEh
Hbj:CViYq
} #YMp,i
<$Kv^Y*
\EfwS% P
/* blkJm9]v
**FileAccess.java ^+l\YB7pD
*//文件访问(定位，写) ?01""Om
package NetFox; K@u."eaD
import java.io.*; ~rfjQPbh9x
FH5bC6
\36;csu
public class FileAccessI implements Serializable{ uz2s-,
.F$AmVTN
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x!Y@31!Dy
RandomAccessFile oSavedFile; @tp7tB ;
long nPos; 8`?j*FV7kq
&1C9K>
7CN[Z9Y^}
public FileAccessI() throws IOException ZUI\0qh+
{ 93eqFCF.
this("",0); 8 =Lv7G%
} 40sLZa)e
P+|8MT0
J7] 60H#P
public FileAccessI(String sName,long nPos) throws IOException #.t{g8W\C
{ Y,"MQFr(o
oSavedFile = new RandomAccessFile(sName,"rw"); *U^hwL
this.nPos = nPos; *M<=K.*\G
oSavedFile.seek(nPos); ]<?)(xz
} wef^o"aP
NS~knR\&
.qPfi] ty
public synchronized int write(byte[] b,int nStart,int nLen) nAC#_\
{ ASU\O3%%
int n = -1; `GWq3c5
try{ >^ar$T;Ys
oSavedFile.write(b,nStart,nLen); R}26"+~
n = nLen; qiryC7.E
} 0-~x[\>>
catch(IOException e) [$Bb'],k
{ U:jf9L2
e.printStackTrace (); h4i$z-!
} ;i?!qB>baX
TRok4uc
`5&V}"lB
return n; W)~.o/;
} %$KO]
L=FvLii.
*g6o ;c
} c9@jyq_H?
ng*E9Puu[
A:J{
/* 4N0nU
**SiteInfoBean.java <5}du9@
*/ !QspmCo+
package NetFox; dkp[?f)x
-{%''(G
tP{$}cEY
public class SiteInfoBean { 291|KG
jP'b! 4
E-iBA(H
private String sSiteURL; //Site's URL x7@HPf
private String sFilePath; //Saved File's Path ?zu{&aOX|
private String sFileName; //Saved File's Name 28yxX431S
private int nSplitter; //Count of Splited Downloading File jdf@lb=5l
Z!eq/
w8ld*z
public SiteInfoBean() (32nI?)a
{//nSplitter的缺省值为5 9?c^~77
//default value of nSplitter is 5 5/ju it
this("","","",5); .)zISa*Xy
} c3t8yifQ
_q4m7C<
='>UKy[=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) O3: dOL/C
{ DdO'
sSiteURL= sURL; Lc?O K"[m
sFilePath = sPath; Acv{XnB
sFileName = sName; tY=TY{RY
this.nSplitter = nSpiltter; c10).zZ
Z?mg1;Q
;BVhkWA
} j!)p NZW.<
.x8$PXjPG
@/FX7O{n:
public String getSSiteURL() 1U7HS2
{ J,Ap9HJt
return sSiteURL; ;P~S/j[ 8
} Q>ytO'v1
.Tv(1HAc2l
9#6/c
public void setSSiteURL(String value) #Q7$I.O]
{ N Z`hy>LF^
sSiteURL = value; i`'^ zR(`i
} H-w|JH>g
<z)G& h@
?Fpl.t~
public String getSFilePath() 18`%WUPnT
{ E%B Gf}h
return sFilePath; SqB|(~S
} D0i30p`
+Bfi/>
}C.{+U
public void setSFilePath(String value) =rF8[Q0K
{ [+z:^a1?V
sFilePath = value; E ET 2|*}
} V p{5Kxq
Y_sVe
]'/]j
public String getSFileName() T_T{c+,Zd$
{ zmRK%a(
return sFileName; Am4(WXVQ
} 2,0F8=L
(=rv `1
UUqj?'Nv
public void setSFileName(String value) nDy=ZsK
{ koZp~W-
sFileName = value; p04+"
} "cM5=;
^mQfXfuL
y@_?3m7B=
public int getNSplitter() ~#\#!H7
{ F JhVbAMd
return nSplitter; He3zV\X[Z
} q/79'>`|ai
4&fnu/,Z
=i?,y+<
public void setNSplitter(int nCount) v19`7qgR(
{ 2zu~#qU[)M
nSplitter = nCount; d 4R+gIA
} e~?]F0/
} J7o?h9
Xs@ ^D,
|0p'p$%
/* cyg>hX{U
**Utility.java k5(yf~!c
*/ n^#LB*q
package NetFox; &S]v+wF
~7'.{VrU
&Sa~Wtm|*
public class Utility { rK|&u v*b
puF Z~WZ
]{^vs'as\
public Utility() \l5:A]J
{ ]i2\2MTW8
(=V[tI+Ngt
A8GlE
} 3>v0W@C
*DzPkaYD>
//线程睡眠 0EXNq*=EE
public static void sleep(int nSecond) y/eX(l<{
{ Un{ln*AR\
try{ 1s[-2^D+EM
Thread.sleep(nSecond); 'U$VOq?!
} W=]",<
catch(Exception e) z-gG(
{ ZNeqsN{
e.printStackTrace (); \;gt&*$-
} pUGfm
} P@`"MNS
f om"8iL1
//日志 e}AJxBE
public static void log(String sMsg) (OQ @!R&
{ 4[0?F!%
System.err.println(sMsg); #)}bUNc'
} {`CWzk?
ZY$@_DOB}
;@~*z4U
public static void log(int sMsg) >Fk`h=Wd
{ T?{9Z
System.err.println(sMsg); v=-3 ,C
} Qp&ySU8
} h xJgxM
o;_bs~}y
N~_jiVD>
/* Cbs4`D,
**TestMethod.java ?^4sE-C6
*/ IkNt! 2s_
package NetFox; uA`PZ|
ER1mA:8>E
R9G)X]
public class TestMethod { 9yw/-nA
=c^=Yvc7U
WVK-dBU
public TestMethod() l{m~d!w`a
{ ///xx/weblogic60b2_win.exe D-:<]D:
try{ 0.+eF }'H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D#}Yx]Q1
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Am0C|(#Xm
SiteFileFetch fileFetch = new SiteFileFetch(bean); q*TKs#3
fileFetch.start(); g_c)Ts(
} bv>lm56
catch(Exception e){e.printStackTrace ();} jZ,[{Z(N
h!CX`pBM
JMlhBh
} \[I .
$=xQX
b7sE
public static void main(String[] args) >1I2R/'
{ (ul-J4E\O
new TestMethod(); %kFELtx
} 1y-lZ}s_
} aW-o=l@;
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