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)); C4QeDvpI
} >4n+PXRXX
for(int i=0;i<nEndPos.length-1;i++) ;rB6u_5"I.
{ gjj 93
nEndPos = nStartPos[i+1]; `$s)X$W?
} gq'>6vOj
nEndPos[nEndPos.length-1] = nFileLength; 3 p/b
} (O\U /daB
} gi6g"~%@q1
Deg!<[Nw
aUH\Ee^M:R
//启动子线程 YD&|1h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; F9(._ow[
for(int i=0;i<nStartPos.length;i++) GX4QaT%
{ Z_H?WGO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @#RuSc
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Q6"uK
nStartPos,nEndPos,i); gNShOu
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e`i7ah;
fileSplitterFetch.start(); G' Blp
} ,E\h!/X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), OT%0{2c"]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]N*L7AVl
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E{tx/$f
nEndPos = " + nFileLength); g;pR^D'M5C
// fileSplitterFetch[nPos.length-1].start(); jY7=mAd
+R-h ,$\=7
wfgqgPo!v
//等待子线程结束 ?4XnEDAm
//int count = 0; %.mEBI=hs
//是否结束while循环 W'a(oI
boolean breakWhile = false; hd+]Ok7"
l)4O .*
M!1U@6n!=)
while(!bStop) j'K38@M:MN
{ ]' Y|Nl
write_nPos(); !p9)CjQ"
Utility.sleep(500); I>PZYh'.T
breakWhile = true; kv6Cp0uFg
>F1G!#$0
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for(int i=0;i<nStartPos.length;i++) Cyq?5\a
{ |0`hE;Kt7
if(!fileSplitterFetch.bDownOver) C5xag#Z1
{ zuSq+pxL@
breakWhile = false; R}8XRe
break; Wf#VA;d
} _;56^1'T
} $ a?
if(breakWhile) e}'gvm
break; {~SaRB2<'
E<>*(x/\e
A{# Nwd>
//count++; $B;_Jo\|
//if(count>4) NzQ9Z1Mxy
// siteStop(); : [q0S@
} nVE9^')8V
MtS3p>4
v2Bzx/F:
System.err.println("文件下载结束！"); dBSbu=^$)
} v,=v
catch(Exception e){e.printStackTrace ();} Lxv6!?v|
} a5@z:i
*z'8j
"wAf.=F
//获得文件长度 oH^(qZ8W
public long getFileSize() %Y]=1BRk}
{ (D<(6?
int nFileLength = -1; NQfYxB1Yr:
try{ /kgeV4]zR
URL url = new URL(siteInfoBean.getSSiteURL()); hfqqQ!,l!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ~*M$O&
httpConnection.setRequestProperty("User-Agent","NetFox"); r> k-KdS
"g>.{E5
)"Q*G/+2Ie
int responseCode=httpConnection.getResponseCode(); Wy4$*$
if(responseCode>=400) c~0{s>
{ oc7$H>ET1
processErrorCode(responseCode); CS 8jA\
return -2; //-2 represent access is error TX}T|ri
} &$'z
\8S~c8Z~
'$G"[ljr
String sHeader; )[L^Dmd,
0fm*`4Q
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for(int i=1;;i++) hoM|P8 }rh
{ k1^\|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LJFG0 W
//Utility.log(in.readLine()); ]0c+/ \b&
sHeader=httpConnection.getHeaderFieldKey(i); |F[=b'?
if(sHeader!=null) \(~wZd
{ !ErH~<f%K
if(sHeader.equals("Content-Length")) 6KHN&P
{ R\mR$\cS
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x}TS
break; p8}(kHUp(
} QSw<%pcJE@
} ht=P\E
else !}f1`/
break; g13 rx%-
} YO+{,$
} JhHWu<
catch(IOException e){e.printStackTrace ();} +JRF0T
catch(Exception e){e.printStackTrace ();} 2 PqS%`XiS
#3$\Iu
@%/]Q<<q
Utility.log(nFileLength); ~]HN9R^&
yWDTjY/
JL=U,Mr6
return nFileLength; 7F^#o-@=J
} B9R(&<4
.zg8i_
Cx<0 H
//保存下载信息（文件指针位置） N8toxRu
private void write_nPos() |re}6#TgcT
{ \1"'E@+
try{ O.`Jl%
output = new DataOutputStream(new FileOutputStream(tmpFile)); [XVEBA4GI
output.writeInt(nStartPos.length); *&BnF\?m
for(int i=0;i<nStartPos.length;i++) m: n`g1
{ $ _j[2EU
// output.writeLong(nPos); o*WY=
output.writeLong(fileSplitterFetch.nStartPos); ({r*=wAP
output.writeLong(fileSplitterFetch.nEndPos); v+7kU=
} ?BA]7M(,4
output.close(); fhPkEvJ
} XfPFo6
catch(IOException e){e.printStackTrace ();} Wj|alH9<
catch(Exception e){e.printStackTrace ();} Zxr!:t7
} Vd^g9
%nN `|\
{S/yL[S.
//读取保存的下载信息（文件指针位置） j9Ybx#
private void read_nPos() r={c,i
{ `Z:R Ce^
try{ aj8A8ma*}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5=Xy,hmnC
int nCount = input.readInt(); ~h}Fi
nStartPos = new long[nCount]; L`f^y;Y.
nEndPos = new long[nCount]; [B@'kwD\l
for(int i=0;i<nStartPos.length;i++) }En
{ XU!2YO)t;!
nStartPos = input.readLong(); :NJ_n6E
nEndPos = input.readLong(); gE#>RM5D
} )?+$x[f!*
input.close(); Jk@]tAwoM
} |4$M]Mf0
catch(IOException e){e.printStackTrace ();} &'cL%.
catch(Exception e){e.printStackTrace ();} theZ]5_C
} JB!:JML
QaUm1i#
s { #3r
private void processErrorCode(int nErrorCode) S$KFf=0
{ P96pm6H_;
System.err.println("Error Code : " + nErrorCode); X%yO5c\l2
} BA\/YW @
oFOnjK"|F
+"9hWb5
//停止文件下载 n>@oBG)!
public void siteStop() N0hE4t
{ )`^p%k
bStop = true; $kR N h6
for(int i=0;i<nStartPos.length;i++) G\|,5HED
fileSplitterFetch.splitterStop(); 8XbA'% o
rG,5[/l
$w"$r$K9K
} 9x,RvWTb
} ^C2\`jLMY
//负责部分文件的抓取 ]HpA5q1ck
**FileSplitterFetch.java Y*mbjyt[?X
*/ (sVi\R
package NetFox; LC1(Xbf
!i=nSqW
=zwOq(Bh W
import java.io.*; ^CwR!I.D}4
import java.net.*; %,+leKs
2^?:&1:
f/CuE%7BR
public class FileSplitterFetch extends Thread { cwGbSW$t
J\e+}{
9"g6C<
String sURL; //File URL @&[T _l
long nStartPos; //File Snippet Start Position 1S@vGq}
long nEndPos; //File Snippet End Position o)'y.-@Q
int nThreadID; //Thread's ID A*W)bZs.
boolean bDownOver = false; //Downing is over j0@[Br%7
boolean bStop = false; //Stop identical GR\5WypoJ
FileAccessI fileAccessI = null; //File Access interface z=$jGL
2t $j
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException SNY~9:;]f
{ ~on(3|$
this.sURL = sURL; bXS:x
this.nStartPos = nStart; p!s}=wI`
this.nEndPos = nEnd; c'*a{CV4P
nThreadID = id; ZyEHzM{$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 mFHH515
} np~~mdmRK
ek&kv#G
LzYO$Ir:g
public void run() *5xJv
{ u ElAnrm
while(nStartPos < nEndPos && !bStop) q4V7
{ z $MV%F
<8,cuX\
@)K%2Y`
try{ cV`E>w=D0
URL url = new URL(sURL); %Q!`NCe+[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -j&Tc`j_
httpConnection.setRequestProperty("User-Agent","NetFox"); dMrd_1
String sProperty = "bytes="+nStartPos+"-"; Q[#vTB$f
httpConnection.setRequestProperty("RANGE",sProperty); f3UXCp
Utility.log(sProperty); f nI|
$y b4xU
TT-h;'nJ
InputStream input = httpConnection.getInputStream(); S(7ro]U9
//logResponseHead(httpConnection); z)uuxNv[R
}W ^: cp
lSH6>0#B
byte[] b = new byte[1024]; J/3_C6UZ
int nRead; nJ" '
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t+Op@*#%
{ +kFxi2L6
nStartPos += fileAccessI.write(b,0,nRead); pAk/Qxl3eo
//if(nThreadID == 1) cCR+D.F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N:9>dpP}O
} c5mZG7-
\o';"Q1H
2ZQ}7`Y
Utility.log("Thread " + nThreadID + " is over!"); [b$4Shx
bDownOver = true; aj}(E+
//nPos = fileAccessI.write (b,0,nRead); gR@C0
} 5[Pr|AY
catch(Exception e){e.printStackTrace ();} h;jIYxj
} /6_|]ijc
} Y \:0Ev
bb d.
WAn'kA
//打印回应的头信息 [{X^c.8G)
public void logResponseHead(HttpURLConnection con) (L`j0kPN
{ (xq%
for(int i=1;;i++) b?eu jxqg
{ &Ni`e<mP
String header=con.getHeaderFieldKey(i); ~gu3g^<0v
if(header!=null) sUYxT>R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x\Y $+A,P
Utility.log(header+" : "+con.getHeaderField(header)); "al`$%(
else u_).f<mUdF
break; )+Oujt
} r `eU~7
} 3su78et}
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F9*g=
public void splitterStop() %K]euEqs
{ Lq>&d,F06)
bStop = true; 4BwQA#zE
} t5lO'Ll*Q]
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} d9n?v)<v
f}D1|\7
8KH\`5<
/* |_G )qp;
**FileAccess.java WF\)fc#;_o
*//文件访问(定位，写) {$ep7;'d
package NetFox; #);[mW{F
import java.io.*; dZ _zg<
=LTmr1?
=f(cH152T
public class FileAccessI implements Serializable{ |T{C,"9y
f>ZyI{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 aTzjm`F0
RandomAccessFile oSavedFile; %_Yx<wR%
long nPos; 1bw{q.cmD
jzK5-;b
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public FileAccessI() throws IOException !p1qJ [
{ sN("+ sZ.n
this("",0); [ 4;Ii
} H}LS??P
I=;+n-
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public FileAccessI(String sName,long nPos) throws IOException nhN);R~o"1
{ 7u[j/l,
oSavedFile = new RandomAccessFile(sName,"rw"); s[gKc'
this.nPos = nPos; KLX/O1B
oSavedFile.seek(nPos); O+RP3ox"
} jLJ1u/l>;
%_UN<a
#oJ5k8Wy
public synchronized int write(byte[] b,int nStart,int nLen) X w.p
{ p!/[K6u
int n = -1; pZyQY+O
try{ {Q<$Uo6V
oSavedFile.write(b,nStart,nLen); y ?G_y
n = nLen; 'q * Bdx
} R<x'l=,D(
catch(IOException e) .ZMW>U>
{ G Xt4j
e.printStackTrace (); L>Mpi$L
} }Yv\0\~'W|
Bb{!Yh].:A
s`Cy a`
return n; *z'yk*
} 7E!7"2e a
tb?YLxMV
S^Au#1e
} -{ u*qtp
v_<2H'*Q
+PK6-c\r
/* _W3Y\cs,-
**SiteInfoBean.java IcIOC8WC
*/ t\v+ogbk)
package NetFox; umLb+GbI4
",>H(wJ8
p h[\)
public class SiteInfoBean { ?r_l8
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private String sSiteURL; //Site's URL hO[3Z^X
private String sFilePath; //Saved File's Path Gs2p5nL<
private String sFileName; //Saved File's Name @/UfDye
private int nSplitter; //Count of Splited Downloading File (5^ZlOk3
u-"c0@
B}d.#G+_$x
public SiteInfoBean() \M]-bw`
{//nSplitter的缺省值为5 :c8n[+5
//default value of nSplitter is 5 _7a'r</@
this("","","",5); n-QJ;37\
} OlD`uA
0iEa[G3
CVXytS?@x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %i)B*9k
{ ^6p'YYj"5
sSiteURL= sURL; <Q<+4Y{R
sFilePath = sPath; nT#JOmv
sFileName = sName; ) uP\>vRy
this.nSplitter = nSpiltter; TOLl@p]lU
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ngi<v6i
} /NF#+bx
1px\K8
b]gY~cbI8
public String getSSiteURL() F=)eLE{W
{ 6ri\>QrF
return sSiteURL; 7.bN99{xPM
} u}6v?!
+pqM ^3t|y
NHX>2-b
public void setSSiteURL(String value) d`Q7"}uZ
{ 9h(IUD{8
sSiteURL = value; f"&Xr!b.h
} b~7drf
0'$p$K
!F!3Q4
public String getSFilePath() ``?6=mO
{ G%TL/Z40
return sFilePath; @{Py%
} ;_<)JqUh
'4;6u]d)2
Uz8hANN0_
public void setSFilePath(String value) Qu{cB^Ga*
{ "PpjoM ~
sFilePath = value; ST8!i`Q$
} 'b:Ne,<
$R{8z-,Q
<xS=#
public String getSFileName() UCqs}U8
{ zREJ#r
return sFileName; X`20f1c6q>
} |k-XBp
ACBQ3
1"K*._K
public void setSFileName(String value) _LfHs1g4
{ Jme%
sFileName = value; JE%A|R<Jl
} ?p8k{N(1
QV,E#(\5
nx4P^PC
public int getNSplitter() P0\eBS
{ {^RG% &S
return nSplitter; +p/1x'J
} Nh)[rx
ekzjF\!y
4u:0n>nJ1
public void setNSplitter(int nCount) #7z|mVzH
{ q/6UK =
nSplitter = nCount; K%,$ V,#
} uzorLeu
} dhR(_
=hX[
Z6=~1'<X
/* &`:rp!Lc
**Utility.java ~y\:iL//E
*/ ^Qh-(u`
package NetFox; K=kH%ZK
, Fytk34
Q(\ wx
public class Utility { LC'F<MpM
\K`jCsT
q6[}ydV
public Utility() I5pp "*u
{ t9*=
<lld*IH
=l|>.\-
} <NQyP{p
{$TZ}z"DA
//线程睡眠 E#h~V5Tf
public static void sleep(int nSecond) .Dv=pB,u
{ |>sv8/!
try{ 44C+h
Thread.sleep(nSecond); )W9_qmYd"
} /| GH0L
catch(Exception e) NV!4(_~
{ Hhf72IX
e.printStackTrace (); Wu{&;$
} =WRO\lgv.
} 3hJH(ToO
Dt {')
//日志 Y. TYc;
public static void log(String sMsg) _bQL[eXd
{ tBl#o ^
System.err.println(sMsg); /VtlG+dLl
} w4OW4J#
2NR7V*A
=K6c;
public static void log(int sMsg) ta! V=U
{ rUFFF'm\*a
System.err.println(sMsg); "#XtDpGk
} y"R("j $
} ?cBO6^
QeK{MF
T 'i~_R6
/* o4'v> b
**TestMethod.java $n*%v85
*/ &l!$Sw-u;
package NetFox; "z/V%ZK~f
6<76O~hNZ
0o;~~\fq.
public class TestMethod { 9%TT>2#
f=oeF]=I"
#O6 EP#B
public TestMethod() fIEw(k<*
{ ///xx/weblogic60b2_win.exe C@)pmSQ
try{ rys<-i(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); /d]~ly @uI
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #`58F.
SiteFileFetch fileFetch = new SiteFileFetch(bean); "8_,tYAH
fileFetch.start(); .P%ym~S
} zW)gC9_|m-
catch(Exception e){e.printStackTrace ();} E.#6;HHzN
Xv*}1PZH
)[ w&C_>]
} \Jf9npz3
9mm2Vps;
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public static void main(String[] args) x.G"D(
{ u !.DnKu
new TestMethod(); ULTNhq R*n
} /.2u.G
} e7's)C>/'
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