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)); HuLvMYF
} ak_n
for(int i=0;i<nEndPos.length-1;i++) *JArR1J
{ O-(gkE
nEndPos = nStartPos[i+1]; 7hlzuZob+y
} ]?sw<D{
nEndPos[nEndPos.length-1] = nFileLength; sjy/[.4-
} @HQqHO&N
} Esdv+f}4;
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* `3+x
//启动子线程 Owz>g4l r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |33_="
for(int i=0;i<nStartPos.length;i++) {Q021*xt/
{ bQ`2ll*(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '$h0l-mQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 0ky3rFSh1
nStartPos,nEndPos,i); 1VA%xOURh
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m`&6[[)6~
fileSplitterFetch.start(); RveEA/&&
} mXT{c=N)w
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L"L a|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a(_3271
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ' -td/w
nEndPos = " + nFileLength); ^!6T,7B B
// fileSplitterFetch[nPos.length-1].start(); )O,+'w?
yRWZ/,9x
PG{"GiZz=
//等待子线程结束 )uO 3v
//int count = 0; E?h'OR@_ L
//是否结束while循环 5Z>+NKQ
boolean breakWhile = false; F%I*m^7d
uQl=?085
Rhzcm`"
while(!bStop) Og1Hg B3v
{ |@rYh-5
write_nPos(); PmA_cP7~
Utility.sleep(500); x75 3o\u!
breakWhile = true; ]]hsLOM]
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for(int i=0;i<nStartPos.length;i++) 0Wb3M"#9<
{ YK V"bI
if(!fileSplitterFetch.bDownOver) (m() r0:@
{ 2Uy}#n|)r
breakWhile = false; u vyvy
break; F\%PB p
} u>.>hQ
} ~>uu1[/
if(breakWhile) ,-V7~gM%}
break; Lpk`qJ
F~l:WQAj
5XZ\7Z|
//count++; m^;A]0h+
//if(count>4) 6C- !^8[f
// siteStop(); T#3`&[
} `;Xwv)
K 5AArI
YH3[Jvzf4
System.err.println("文件下载结束！"); =k2"1f~e
} s x)x7
catch(Exception e){e.printStackTrace ();} tC&jzN"
} |DUOyQ
Es&'c1$^s
$yZ(ws
//获得文件长度 Q oWjC
public long getFileSize() KV|ywcGhT
{ d[&Ah~,
int nFileLength = -1; kOV6O?h
try{ ;'oi7b
URL url = new URL(siteInfoBean.getSSiteURL()); 84c[Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 7jPn6uz>w
httpConnection.setRequestProperty("User-Agent","NetFox"); :Oc&{z?q
(*G'~gSX
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int responseCode=httpConnection.getResponseCode(); E#`JH
if(responseCode>=400) {\5-b:#_
{ Ip*[H#h
processErrorCode(responseCode); :i]g+</
return -2; //-2 represent access is error Cgn@@P5ZC
} |dqvv
1A{iUddR
QW>(LGG=
String sHeader; h<FEe~
[zhcb+^5l
O;RNmiVoq
for(int i=1;;i++) ;Rd\yAG
{ 6gD|QC~;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); l`vr({A
//Utility.log(in.readLine()); k6??+b:rE
sHeader=httpConnection.getHeaderFieldKey(i); y:dwx*Q9I
if(sHeader!=null) ?v Z5 ^k
{ 4.'KT;[_1/
if(sHeader.equals("Content-Length")) B=hJ*;:p
{ !gG\jC~n
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0u8(*?
break; 5U.,iQ(d
} )q'~<QxI\
} uH8`ipX
else &>z}u&oF
break; Bk8 '*O/)
} ;/ao3Q
} 1a;&&!X
catch(IOException e){e.printStackTrace ();} UE/N-K)`
catch(Exception e){e.printStackTrace ();} %M;{+90p>t
0= -D
g#<M/qn
Utility.log(nFileLength); dWhF[q"
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*,p16"Q;
return nFileLength; Vr<ypyC
} D(gpF85t
-QP&A >]7
gfAVxMg
//保存下载信息（文件指针位置） 'gv7&$X}4
private void write_nPos() g bwg3$!9
{ !Mk:rO-L
try{ ,__|SnA.
output = new DataOutputStream(new FileOutputStream(tmpFile)); s`"ALn8m
output.writeInt(nStartPos.length); .X(ocs$}
for(int i=0;i<nStartPos.length;i++) da53XEF&
{ ^p!bteA>
// output.writeLong(nPos); LdYaJh~h
output.writeLong(fileSplitterFetch.nStartPos); |h65[9DMP
output.writeLong(fileSplitterFetch.nEndPos); -}r(75C
} ^Sz?c_<2P
output.close(); d 3}'J
} od~`q4p1(-
catch(IOException e){e.printStackTrace ();} js8\"
catch(Exception e){e.printStackTrace ();} 7<c&)No;
} S~4HFNe^&
i*%2 e)
}V %b
//读取保存的下载信息（文件指针位置） \^%5!
private void read_nPos() Y/w) VV
{ 9 ulr6
try{ P1mPC
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _G5MQ%z
int nCount = input.readInt(); yy-\$<j
nStartPos = new long[nCount]; +qEvz<kch
nEndPos = new long[nCount]; #]5|Qhrr+
for(int i=0;i<nStartPos.length;i++) WS)u{ or
{ O@bDMg
nStartPos = input.readLong(); CmPix]YMQ
nEndPos = input.readLong(); ICgyCsZ,
} $\@yH^hL
input.close(); 5PlTf?Ao
} t#h<'?\E
catch(IOException e){e.printStackTrace ();} $MG. I[h
catch(Exception e){e.printStackTrace ();} `;R|SyrX
} -/#tQ~{gs
<ArP_! `3
kVZ5>D$
private void processErrorCode(int nErrorCode) ywV8s|o
{ c/57_fOK
System.err.println("Error Code : " + nErrorCode); 20f):A6
} R4|<Vp<U2
l7r!fAV-f
IK-E{,iKc
//停止文件下载 `-N&cc
public void siteStop() <~Tlx:
{ wp,z~raaS
bStop = true; S,,3h0$X
for(int i=0;i<nStartPos.length;i++) Az2$\
fileSplitterFetch.splitterStop(); :22IY>p
Th%1eLQ
b\w88=|
} PaFJw5f
} ft[g1
//负责部分文件的抓取 Yn}_"FO'
**FileSplitterFetch.java TPds)osZT
*/ >cD+&h34
package NetFox; w%k)J{\
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#7U,kTj9
import java.io.*; '.@R_sj
import java.net.*; 5b[:B~J
6Bp{FOj:Ss
#?i#q%q
public class FileSplitterFetch extends Thread { 5@Q4[+5&_
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String sURL; //File URL lq_W;L
long nStartPos; //File Snippet Start Position 88U4I
long nEndPos; //File Snippet End Position _A)<"z0E
int nThreadID; //Thread's ID ZjEO$ts=@
boolean bDownOver = false; //Downing is over *ftJ(
boolean bStop = false; //Stop identical Prhq ~oI4
FileAccessI fileAccessI = null; //File Access interface ,/W<E
$YSD%/c
&bj :,$@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _:'m/K3Ee
{ VJCh5t*
this.sURL = sURL; S53%*7K.
this.nStartPos = nStart; Whd4-pR8
this.nEndPos = nEnd; z[v5hhI)4
nThreadID = id; uU.9*B=H9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |-_5ouN.
} 54J<ZXCs
d=qpTb;(
^MJGY,r6b
public void run() {u.V8%8
{ NTL#!
while(nStartPos < nEndPos && !bStop) aG}9Z8D
{ o@LjSQ5!
faO8 &
?3}UO:B
try{ 2J4|7UwJ
URL url = new URL(sURL); 6eDIS|/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j|`{ 1`'
httpConnection.setRequestProperty("User-Agent","NetFox"); @L<[38
String sProperty = "bytes="+nStartPos+"-"; 2hJ{+E.m
httpConnection.setRequestProperty("RANGE",sProperty); w ^<Y5K
Utility.log(sProperty); Km <Wh=
cZ!s/^o?f
lIFt/
InputStream input = httpConnection.getInputStream(); ^Nsl5
//logResponseHead(httpConnection); @5?T]V g
Q5,@P?
H;sQ]:.*]
byte[] b = new byte[1024]; R^B2J+O
int nRead; @i{JqHU"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3K?0PRg
{ mzT} C&hfP
nStartPos += fileAccessI.write(b,0,nRead); )b%c]!
//if(nThreadID == 1) "{x~j\<
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); K%pmE?%,8
} #dpt=
<,E*,&0W
99ha/t
Utility.log("Thread " + nThreadID + " is over!"); 0X0D8H(7Q
bDownOver = true; ;n;^f&;sJ
//nPos = fileAccessI.write (b,0,nRead); s3+O=5
} gw*d"~A
catch(Exception e){e.printStackTrace ();} Xl/G|jB9
} /hX"O?^
} @&Nvb.5nT
KV5lpN PC
4*+EUJ|
//打印回应的头信息 7@lXN8_f
public void logResponseHead(HttpURLConnection con) j&Hn`G
{ *(vq-IE\$
for(int i=1;;i++) -YuvEm#f
{ h+74W0 $
String header=con.getHeaderFieldKey(i); <y.D0^68
if(header!=null) "q`%d_
//responseHeaders.put(header,httpConnection.getHeaderField(header)); EkL\~^
Utility.log(header+" : "+con.getHeaderField(header)); uf;q/Wr
else Vd?v"2S(9
break; m_(hCY=Q$
} i52R,hz
} yX-xVvlv@
s^oNQ}
\9}5}X_x.
public void splitterStop() @qC:% |>
{ c"YK+2
bStop = true; 0&.lSwa
} q9 ;\B&
b;t]k9:"L
-Y[-t;
} t~M<j|]k
y[|g!9Rp
=+"'=o
/* ;yZ N "r
**FileAccess.java RE.@ +A
*//文件访问(定位，写) iCK$ o_`?
package NetFox; O5{XT]:
import java.io.*; u.[JYZ
V1:3
*h4m<\^U
public class FileAccessI implements Serializable{ Eo Urc9G2
<!N;(nZ9}O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z}8YrVr@
RandomAccessFile oSavedFile; j?,*fp8
long nPos; u W|x)g11a
-*lP1Nbp
A C^[3
public FileAccessI() throws IOException ,xz^k/.
{ vQ/\BN
this("",0); *_QHtZG
} NNE,| :
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K D-_~uIF
public FileAccessI(String sName,long nPos) throws IOException PbPP1G')
{ ]= NYvv>H
oSavedFile = new RandomAccessFile(sName,"rw"); Dq?HUb^X
this.nPos = nPos; +zdkdS,2<
oSavedFile.seek(nPos); +r$.v|6
} / 3k\kkv!
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z{g<y^Im+E
public synchronized int write(byte[] b,int nStart,int nLen) 5 WppV3;
{ u-9t s
int n = -1; _;q-+"6L;
try{ `fkrik
oSavedFile.write(b,nStart,nLen); na3kHx@
n = nLen; D&r8V;G[[
} 8-5jr_*
catch(IOException e) mG~y8nUtp
{ qE72(#:R*
e.printStackTrace (); -HsBV>C
} t4k'9Y:\Q
<PN;D#2bh
/>[6uvy#Q
return n; 4)iEj
} ijqdZ+
&{/>Sv!6#
G r|@CZq
} I=%sDn
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[T}]Ma*CS
/* =+h!JgY/L
**SiteInfoBean.java rgzI
*/ <M OL{jan
package NetFox; IVzA>Vd
j& o+KV
tN3 {7'\7
public class SiteInfoBean { wmr%h q
b2=Q~=Wc
+Jka:]MW!
private String sSiteURL; //Site's URL px>>]>ZMH
private String sFilePath; //Saved File's Path U9o*6`"o
private String sFileName; //Saved File's Name Hs}"A,V
private int nSplitter; //Count of Splited Downloading File ]A]E)*
70 UgKE
!(_xu{(DL
public SiteInfoBean() K2rS[Kdfaq
{//nSplitter的缺省值为5 z83:a)U
//default value of nSplitter is 5 `VFl|o#H
this("","","",5); ZU.)K>'
} :ZfUjqRE
,N7l/6
;vclAsJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e~s7ggg2k
{ '+I 2$xE
sSiteURL= sURL; K}=8:BaUL
sFilePath = sPath; UVCMB_T
sFileName = sName; 01c/;B
this.nSplitter = nSpiltter; X_({};mz
<SM&VOiaOz
Mr NOcx&
} lMzCDx!m
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ms\/=96F
public String getSSiteURL() ar qLp|
{ y[WYH5&DJ
return sSiteURL; D ,ZNh1xt
} mYjiiql~
khN:+V|
KvJP(!{
public void setSSiteURL(String value) )]b@eGNGj
{ K# i*9sM
sSiteURL = value; _ K+V?-=
} y5Wqu9C\Io
0"<;You
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public String getSFilePath() )|h;J4V
{ <,X+`m&
return sFilePath; ?tC}M;~
} g.Caapy
B mBzOk^
/yw\(|T
public void setSFilePath(String value) 8@W/43K8-
{ `^bvj]>l
sFilePath = value; [OoH5dD
} ;p#Z:6
-6~dJTm[t
1|EU5<
public String getSFileName() p-yOiG8b}
{ a,57`Ks+n<
return sFileName; >,"D9!
} !!+/Wgd:6
[mB(GL
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public void setSFileName(String value) [rUh;_b\D
{ ]k`Fl,"
sFileName = value; 4'{hI;&a&
} 3^A/`8R7K
,F?~'-K
28Ssb|
public int getNSplitter() ;x3 ]4^
{ J<($L}T*$
return nSplitter; nhQ44qRgQ
} AeY$.b
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W]!@Zlal
public void setNSplitter(int nCount) l\sS?
{ 2 -p
nSplitter = nCount; ycl>git]
} ]EVe@
} o3i,B),K
Xc9p;B>^Ts
<(bCz>o|
/* R%)2(\
**Utility.java RlslF9f
*/ j""y2c1
package NetFox; .,ppGc|*
"doU.U&u
o! 2n}C
public class Utility { 3!"b guE
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|`k1zc)9
public Utility() RvPniT(<?
{ 0[2BY]`Z.
(ifqwl62
FD XWFJ
} E*r
@tE&<[e
//线程睡眠 Rg8m4xw
public static void sleep(int nSecond) s}[A4`EWH
{ ;o_V!<$
try{ 43{_Y]
Thread.sleep(nSecond); PQU3s$
} w;yiX<t<
catch(Exception e) rF8W(E_=
{ }1a<{&
e.printStackTrace (); ?`N57'iPb
} l`v +sV^1
} _>gXNS r4u
'&.)T2Kw
//日志 R8=I)I-8
public static void log(String sMsg) ?ae[dif
{ v9t47>V
System.err.println(sMsg); ^)9MzD^_nV
} "RV`L[(P*k
}&Wp3EWw
|8DH4*y!
public static void log(int sMsg) Z^'?|qFj!
{ &J lpA<^s;
System.err.println(sMsg); j.=UI-&m
} |<j,Tr1[
} !"`@sd~
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RjR&D?dc
/* C@TN5?Z
**TestMethod.java {[M0y*^64$
*/ o~OwE7H)A
package NetFox; z`emKFbv
>%uAQiU
:rz9M@7
public class TestMethod { 3~[`[4n^
p@?7^nIR*u
Sk6b`W7$
public TestMethod() =_$XP
{ ///xx/weblogic60b2_win.exe H Z;ZjC*
try{ [+g(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ZdE>C
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <ICZ"F`S
SiteFileFetch fileFetch = new SiteFileFetch(bean); j!zA+hF(
fileFetch.start(); _'!aj+{
} d] b~)!VW
catch(Exception e){e.printStackTrace ();} Xt</ -`
:r1;}hIA9
`ir&]jh.A
} "rme~w Di
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"C_T]%'Wm
public static void main(String[] args) .ocx(_3G
{ =)(3Dp
new TestMethod(); !1ML%}vvB,
} E S#rs="
} mgi,b2
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