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)); WvR}c
} "~GudK &
for(int i=0;i<nEndPos.length-1;i++) pt=[XhxC(>
{ H`fkds
nEndPos = nStartPos[i+1]; :QN,T3i'/3
} \4V'NTjB
nEndPos[nEndPos.length-1] = nFileLength; GU!|J71z
} aPWFb.JO4
} [QeKT8
7"M7N^
}L@YLnc%
//启动子线程 9~N7hLT
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %e_WO,R
for(int i=0;i<nStartPos.length;i++) U9Y'eP.2
{ u+{5c5_
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]SK(cfA`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), DK:d'zb
nStartPos,nEndPos,i); lk8VJ~2d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YTY0N5["
fileSplitterFetch.start(); IUzRE?Kzf
} L&l>?"_
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `OduBUI]]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Y5K!DMKY
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Q&wBX%@^L
nEndPos = " + nFileLength); kQ|}"Tw7
// fileSplitterFetch[nPos.length-1].start(); wd u>3Ch"y
sW[42A
i3YAK$w;&
//等待子线程结束 aX0sy\Z]j
//int count = 0; X!r!lW
//是否结束while循环 enZW2o97c
boolean breakWhile = false; ${`\In_?O
XxV]U{i!
0ro)e~_@*
while(!bStop) 3fpX
{ GJ!usv u
write_nPos(); G.L4l|%W
Utility.sleep(500); {Ke3
breakWhile = true; F/mD05{
8amtTM
594$X@!v
for(int i=0;i<nStartPos.length;i++) #~(@Ka.eA0
{ IDv@r\Xw
if(!fileSplitterFetch.bDownOver) ci,o'`Q
{ W.>yIA%
breakWhile = false; N+h|Ffnp
break; x%LWcT/
} n_iq85
} x}72jJe`
if(breakWhile) ;0@"1`
break; 7v1}8Uk
SxMh '
I#9A\.pO
//count++; g=a-zg9LX
//if(count>4) :s*&_y
// siteStop(); 'v4AM@%u
} T<P4+#JK
QD7>S(p
DAJh9I
System.err.println("文件下载结束！"); 'M YqCfIK
} `4XfT.9GT
catch(Exception e){e.printStackTrace ();} k5W5 9tz
} uPb9j;Q?
N/]TZu~k z
RtK/bUa
//获得文件长度 f'*HP%+Y
public long getFileSize() >[ywrB ?T
{ c~@I1M
int nFileLength = -1; U.d*E/OR5
try{ lkBab$S)
URL url = new URL(siteInfoBean.getSSiteURL()); O`H[,+vm[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 350y6pVh
httpConnection.setRequestProperty("User-Agent","NetFox"); DtyT8kr
h1J-AfV
.3oFSc`q
int responseCode=httpConnection.getResponseCode(); jUdW o}/
if(responseCode>=400) &9IMZAo
{ BYP,}yzA
processErrorCode(responseCode); tlG&PVvr
return -2; //-2 represent access is error ;v#~o*
} k:R9wo
LKztGfy
Q-BciBh$
String sHeader; W>'R<IY4#N
s|YY i~
-x5^>+Y4
for(int i=1;;i++) o"K{^ L~u
{ +n1}({7m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *COr^7Kf5
//Utility.log(in.readLine()); QR<IHE{~8
sHeader=httpConnection.getHeaderFieldKey(i); C'kd>LAGu
if(sHeader!=null) l{vi{9n)
{ w~Es,@
if(sHeader.equals("Content-Length")) XgU]Ktl
{ sg{>-KHM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 4d[:{/+Q
break; h?fv:^vSi
} i5V ly'Q
} H|==i2V{
else ]'MLy#9
break; *(s)CWf
} {H"xC~.
} 5zfPh`U>1
catch(IOException e){e.printStackTrace ();} %;9wToyK>
catch(Exception e){e.printStackTrace ();} |\Jpjm)?
2~~Q NWN
z&9vKF
Utility.log(nFileLength); sm/l'e
;%hlh)k$
:E]A51
return nFileLength; m3K8hL/
} n+j'FfSz
7J7uHl`yq`
592q`m\
//保存下载信息（文件指针位置） ?ZE1>L7e
private void write_nPos() FtT+Q$q=
{ (Kv[~W7lb
try{ cqi: Rj
output = new DataOutputStream(new FileOutputStream(tmpFile)); $nBzYRc"3
output.writeInt(nStartPos.length); M*{EK
for(int i=0;i<nStartPos.length;i++) 1/JgirVA
{ og!Uq]U/y
// output.writeLong(nPos); \"5%w *vl
output.writeLong(fileSplitterFetch.nStartPos); _D[vMr[
output.writeLong(fileSplitterFetch.nEndPos); {BDp`uZ
} d|w%F=
output.close(); T'0Ot3m`
} =AGsW
catch(IOException e){e.printStackTrace ();} ci6j"nKci
catch(Exception e){e.printStackTrace ();} [gQ*y~N
} q/<.^X
s0qA8`Yu
2y v'DS
//读取保存的下载信息（文件指针位置） mf^(Tq[
private void read_nPos() )nTOIfP2
{ mvlK~c8
try{ WwPfz<I
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gfFP-J3cN
int nCount = input.readInt(); x^;nQas;
nStartPos = new long[nCount]; qbFzA i
nEndPos = new long[nCount]; _hM3p
for(int i=0;i<nStartPos.length;i++) +mYD DlvI
{ rG}o!I`z
nStartPos = input.readLong(); zf4@:GM`
nEndPos = input.readLong(); &=xm>;`3
} }`\+_@w
input.close(); gNo.&G [
} owJPEx
catch(IOException e){e.printStackTrace ();} }I9\=jT
catch(Exception e){e.printStackTrace ();} $+R0RqV$V~
} ie=tM'fb
iw12x:
7P.C~,+D%P
private void processErrorCode(int nErrorCode) YSs9BF:a
{ $:t;WXc.<
System.err.println("Error Code : " + nErrorCode); r,EIOcz:
} )1Z*kY?f!
Z~9\7QJn
w-"o?;)a
//停止文件下载 %, XyhS5[o
public void siteStop() [x'xbQLGd
{ vB#&XK.aW
bStop = true; Ud\Jc:DG
for(int i=0;i<nStartPos.length;i++) WpWnwQY`#
fileSplitterFetch.splitterStop(); \:'=ccf
U;LbP-{B
AJI,>I,}}
} Wu,'S;>C
} bH~ue5q
//负责部分文件的抓取 qR--lvO
**FileSplitterFetch.java 7fgA)dU:K
*/ BOoLs(p
package NetFox; $7T3wv9
BI3Q~ADV
MrXhVZ"d*
import java.io.*; )?:V5UO\
import java.net.*; =O<Ul~JRK
+q|2j>k@
W52AX.Nm
public class FileSplitterFetch extends Thread { %mAgE\y25
ez"Xb 7
Z1wN+Y.CA
String sURL; //File URL ;%"UZ~]f
long nStartPos; //File Snippet Start Position o=X6PoJN_
long nEndPos; //File Snippet End Position {]n5h#c 5*
int nThreadID; //Thread's ID @K7#}7,t
boolean bDownOver = false; //Downing is over U:M?Ji5CY
boolean bStop = false; //Stop identical /0uZ(F|>I
FileAccessI fileAccessI = null; //File Access interface #e((F,1z
Bq#?g@V
weEmUw Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException rLw,?
{ Ont4-AP
this.sURL = sURL; 9_n!.zA<
this.nStartPos = nStart; i<YatW~Pu
this.nEndPos = nEnd; |-bSoq7t
nThreadID = id; cP''
fileAccessI = new FileAccessI(sName,nStartPos);//定位 L6fc_Mo.EE
} b?hdWQSW7
7q<I7Wt
QU2\gAM
public void run() !NUsfd
{ Rf+ogLa=
while(nStartPos < nEndPos && !bStop) %`t;5kmR
{ }H&NR?Ax
Ix93/FAn
ZTfs&5
try{ D0Oh,Fe#M\
URL url = new URL(sURL); + G#qS1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y]xG@;4M
httpConnection.setRequestProperty("User-Agent","NetFox"); :[3{-.c
String sProperty = "bytes="+nStartPos+"-"; A% 9TS/-p
httpConnection.setRequestProperty("RANGE",sProperty); &B1d+.+
Utility.log(sProperty); ]rO`eN[~U
)2C_6eR
g>_lU vSE
InputStream input = httpConnection.getInputStream(); K, ae-#wgb
//logResponseHead(httpConnection); OW<i"?0
k6_RJ8I
HeZ! "^w
byte[] b = new byte[1024]; 7hqa|
int nRead; %3M(!X:[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t,4q]Jt
{ AF g*
nStartPos += fileAccessI.write(b,0,nRead); O4ciD1
//if(nThreadID == 1) B @H.O!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); , |CT|2D>
} rR@ t5
Z"<aS&GH
kz\ D-b
Utility.log("Thread " + nThreadID + " is over!"); JEL=,0J
bDownOver = true; DBANq\
//nPos = fileAccessI.write (b,0,nRead); 9->E$W
} (9]`3^_,J
catch(Exception e){e.printStackTrace ();} ,R5NKWo
} <7fF9X
} -yHVydu=
8;mn7XX
Fy3&Emu
//打印回应的头信息 |#q5#@,
public void logResponseHead(HttpURLConnection con) Ml1yk)3G
{ oqH811
for(int i=1;;i++) 2T3v^%%j
{ {|c <8
String header=con.getHeaderFieldKey(i); |FGt'
if(header!=null) b&f;p}C24
//responseHeaders.put(header,httpConnection.getHeaderField(header)); hPLQ)c?
Utility.log(header+" : "+con.getHeaderField(header)); ^B8%Re%
else $p30?\
break; i% 19|an
} .<}(J#vC
} z1XFc*5
kFZw"5hb
PXof-W
public void splitterStop() h4N!zj[
{ J;,6ydf8!
bStop = true; DksSD
} %B5.zs]Of
)F4H'
v_?0|Ei[
} C8>zr6)1
M/C7<?&
Aq@_^mq1A
/* q[`)A?Ae
**FileAccess.java 7Gd)=Q{uur
*//文件访问(定位，写) 0|E!e
package NetFox; N>!RKf:ir
import java.io.*; "PK\;#[W|
NXb_hF
KSU?Tg&JR
public class FileAccessI implements Serializable{ 6*9hAnH
% \p:S)R
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]CsF} wr'z
RandomAccessFile oSavedFile; Z? u\
long nPos; ]`)50\pdw
Cy-q9uTm
v*`$is+
public FileAccessI() throws IOException 8gwJ%"-K
{ 5 fY\0
this("",0); JYB"\VV
} j3jf:7 /\
2V%si6
#D~atgR
public FileAccessI(String sName,long nPos) throws IOException >Vz Gx(7q
{ (~}IoQp>
oSavedFile = new RandomAccessFile(sName,"rw"); >U.TkB
this.nPos = nPos; ^vmT=f;TM
oSavedFile.seek(nPos); F!OVx<
} awLN>KI]</
fr kDf-P
Sd/?xyF1(
public synchronized int write(byte[] b,int nStart,int nLen) d~@&*1}
{ o"dX3jd
int n = -1; w=5D>]
try{ ovJ#2_
oSavedFile.write(b,nStart,nLen); E/z^~;KA
n = nLen; ~H!s{$.5
} '0)a|1,
catch(IOException e) fQ c%a1'
{ MUsF/1
e.printStackTrace (); d7s? c
} WtOpxAq
k4r;t: O^
Mqc"
return n; AB<|iJC
} ?Iy$'am]L
_ #]uk&5a
QSPneYD
} 9[K".VeT]
C[MZ9r
OCmF/B_
/* 6' }oo'#~
**SiteInfoBean.java .v;$sst5y
*/ >a7'_n_o
package NetFox; >MD['=J[d
6U[`CGL66
t=M:L[bis;
public class SiteInfoBean { C5oslP/@
sUA==k
9a}rE
private String sSiteURL; //Site's URL <?UbzT7X
private String sFilePath; //Saved File's Path 1%~yb Q
private String sFileName; //Saved File's Name EUH&"8 L
private int nSplitter; //Count of Splited Downloading File 1vKc>+9
(n:d {bKV
_Kdqa%L !
public SiteInfoBean() :L gFd
{//nSplitter的缺省值为5 1xN6V-qk
//default value of nSplitter is 5 z%-Yz-G9
this("","","",5); J60XUxf
} 5u +U^D
'q%56WAJ
pleLdGq
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xL8r'gV@
{ 6UK{0\0
sSiteURL= sURL; mYLqT$t.+
sFilePath = sPath; }z{2~ 0,
sFileName = sName; U6^x(2De
this.nSplitter = nSpiltter; /RD@ [ 8
Za68V/Vj
y)iT-$bQ
} $D{KXkrd
*Kj*|>)
.^6;_s>FN
public String getSSiteURL() a+A^njk
{ +oa\'.~?
return sSiteURL; ,#&\1Vxf
} KwGk8$ U
VN!`@Ci/
S+(TRIjk
public void setSSiteURL(String value) #'5|$ug[
{ ):"Z7~j=
sSiteURL = value; al>^}:
} RsV<4$
A9Cq(L_H
rg Gm[SL*<
public String getSFilePath() m(MPVY<X
{ ?sfas57&y
return sFilePath; $|+q9o\
} Ia_I~ U$
*Ju$A
K.3)m]dCl
public void setSFilePath(String value) WJH-~,u
{ +M4X r*
sFilePath = value; thG;~W
} &+V6mH9m@
Z*&y8;vUQ
n0|oV(0FE
public String getSFileName() \Tf[% Kt x
{ ~)>O=nR
return sFileName; #oBMA
} DUBEh@
ZH'- >/
VB 53n'
public void setSFileName(String value) ZlaU+Y(_[
{ *sNZ.Y:.
sFileName = value; [:M:6JJ
} -L%J,f[&,
/.PjHTM<
Uc oVp}vl
public int getNSplitter() kLc}a5;
{ %eJolztKZ
return nSplitter; ,H6*9!Dv2
} 6z;C~_BV
u!kC+0Y
I*,!zym
public void setNSplitter(int nCount) tBR"sBiws
{ V>"nAh]}.
nSplitter = nCount; hf5yTs
} 80qSPitj
} yX%q7ex
)_[eqr
>K]s)VuWR
/* kmfz=q?
**Utility.java J<K-Yeph
*/ <{$0mUn;s|
package NetFox; M0Eq 7:Ba
-M]NdgI
!~X[qT
public class Utility { s?qRy 2
%V r vu5
fP|rD[
public Utility() F_28q15~:
{ pPI'0x
~W?F.
o}EipTL
} +Fn^@/?yC
"9mVBa|Q
//线程睡眠 DeqTr:
public static void sleep(int nSecond) kR+xInDM*
{ CKC%|xke
try{ y2"PKBK\_
Thread.sleep(nSecond); Xx.4K>j+j
} 3O{*~D&n
catch(Exception e) ?&qa3y)wX:
{ +rT%C&ze
e.printStackTrace (); &yu3nA:7D
} c eH8
} UNx|+
z^@.b
//日志 IZr~h9
public static void log(String sMsg) [VvTR#^
{ 7d9kr?3(U
System.err.println(sMsg); jg2UX
} cvoE4&m!
T6T3:DG_B
px|y_.DB2x
public static void log(int sMsg) PKDzIA~T
{ x#wkODLqi
System.err.println(sMsg); m8Wv46%
} b=V"$(Q
} ,7` /D
!Q-h#']~L
&ZkY9XO
/* JCL+uEX4S
**TestMethod.java !v^{n+
*/ U<T.o0s=
package NetFox; )Dg;W6
.Vohd@s9l
"nkj_pC
public class TestMethod { 0Dx,)C
(#|CL/&
f9+J}
public TestMethod() G~$.Af!9W
{ ///xx/weblogic60b2_win.exe $P=B66t ^
try{ + F{hFuHV
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); D'{NEk@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Vrwy+o>:X
SiteFileFetch fileFetch = new SiteFileFetch(bean); bn$('
fileFetch.start(); z%lu%
} 'hEvW
catch(Exception e){e.printStackTrace ();} VnZRsFY<^
].=~C"s,a
DC&3=Nd
} pQQN8Y~^Y
<)hA?3J
{ylY"FA
public static void main(String[] args) }01c7/DRP<
{ _*tU.x|DP
new TestMethod(); qh|t}#DrR
} !ucHLo3:
} `"7}'|
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