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)); BI}Cg{^km
} 3 SGDy]
for(int i=0;i<nEndPos.length-1;i++) HOh!Xcu
{ CWP2{
nEndPos = nStartPos[i+1]; I15{)o(8$
} c\V7i#u[d;
nEndPos[nEndPos.length-1] = nFileLength; )@'}\_a3[]
} C=4Qlt[`
} P}G+4Sk
D{~fDRR
y<bDTeoo
//启动子线程 Iy3GE[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7 ^mL_SMj
for(int i=0;i<nStartPos.length;i++) FtC^5{V+V
{ r{%qf;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >u8gD6X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *C=>X193U
nStartPos,nEndPos,i); *U\`CXn;
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;l-!)0U
fileSplitterFetch.start(); w(TJ*::T
} QW~1%`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V}NbuvDB@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1|6%evPu(
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", nL.<[]r
nEndPos = " + nFileLength); J{&H+rd
// fileSplitterFetch[nPos.length-1].start(); r_;Nt
=6|&Jt
g^ i&gNDx
//等待子线程结束 ; p{[1
//int count = 0; _W'-+,
//是否结束while循环 \A6B,|@
boolean breakWhile = false; :'&brp3ii=
Zdo'{ $
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while(!bStop) k/gZ,
{ Q7COQ2~K
write_nPos(); H =^`!
Utility.sleep(500); Sw^u3
breakWhile = true; x*&|0n.D
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for(int i=0;i<nStartPos.length;i++) wtV#l4
{ X<; f
if(!fileSplitterFetch.bDownOver) Jl9k``r*
{ fku<,SV$O4
breakWhile = false; 4^OY C
break; %lGfAYEM=
} p >t#@Eu|
} cXOK)g#
if(breakWhile) &7wd?)s
break; @\P;W(m.i
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M$8^91%4B
//count++; t=O8f5Pf{
//if(count>4) KC#q@InK
// siteStop(); 8rS:5:Hi
} X~,aNRy
_v=SH$O+
Q=20IQp
System.err.println("文件下载结束！"); z4]api(xZ
} jc f #6
catch(Exception e){e.printStackTrace ();} EeRX+BM,
} c[1oww
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!*. -`$x
//获得文件长度 V2|aN<Sx<
public long getFileSize() :|8M`18lZ
{ {"QNJq#:
int nFileLength = -1; Um-[~-
try{ FfPar:PHj
URL url = new URL(siteInfoBean.getSSiteURL()); k<{{*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); spPNr
httpConnection.setRequestProperty("User-Agent","NetFox"); oVfLnI;
&,CiM0
P8)=Kbd
int responseCode=httpConnection.getResponseCode(); j*jo@N|
if(responseCode>=400) }\:NuTf
{ &_|#.
processErrorCode(responseCode); )vb*Ef
return -2; //-2 represent access is error > eIP.,9
} zSja/yq
1gy.8i
+sUFv)!4
String sHeader; #"\gLr_:m
,+{LYF
Pjjewy1}^
for(int i=1;;i++) i,4>0o?
{ CZI66pDy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W_8wed:b
//Utility.log(in.readLine()); {|:;]T"y
sHeader=httpConnection.getHeaderFieldKey(i); jesGV<`?l
if(sHeader!=null) Rt!FPoN,y
{ m6CI{Sa](l
if(sHeader.equals("Content-Length")) @A89eZbW
{ <\ :Yk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ix=}+K/
break; YccH+[X;
} >X4u]>X
} f;gw"onx8F
else T<p !5`B1
break; EYEnN
} h+&OQ%e=8
} ,\n&I(
catch(IOException e){e.printStackTrace ();} DBD%6o>]K
catch(Exception e){e.printStackTrace ();} &NoS=(s,
D9 |n)f
MET' (m
Utility.log(nFileLength); $79=lEn,
[8,yF D_U
^ ALly2
return nFileLength; 8'nVwb8I
} giIWGa.a+
@u]rWVy;\[
\$e)*9)
//保存下载信息（文件指针位置） *b/`Ya4
private void write_nPos() E5xzy/ZQ
{ ZR]25Yy
try{ )~] (&
output = new DataOutputStream(new FileOutputStream(tmpFile)); NzOo0tz:
output.writeInt(nStartPos.length); IS 2^g>T#1
for(int i=0;i<nStartPos.length;i++) <_tT<5'[$u
{ D (mj7oB
// output.writeLong(nPos); ;y\IqiA{o
output.writeLong(fileSplitterFetch.nStartPos); (Dl$kGn
output.writeLong(fileSplitterFetch.nEndPos); W$OG(m!W>
} s1NKLt
output.close(); FUjl8b-|
} sOJQ,"sB
catch(IOException e){e.printStackTrace ();} !&/{E [
catch(Exception e){e.printStackTrace ();} *HO}~A%Lx
} CcFn.omA
3.W@ }
3#&7-o
//读取保存的下载信息（文件指针位置） |>htvDL
private void read_nPos() LBsluT
{ >>o dZL
try{ OJ$]V,Z00x
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J/GSceHF
int nCount = input.readInt(); $[&*Bj11Yg
nStartPos = new long[nCount]; G<f@#[$'
nEndPos = new long[nCount]; af+IP_6 .
for(int i=0;i<nStartPos.length;i++) 80/F7q'tn
{ .#Z%1U%P.
nStartPos = input.readLong(); e5B Qr$j
nEndPos = input.readLong(); ~ga`\%J
} TXk?#G\o
input.close(); % !>I*H
} g,95T Bc
catch(IOException e){e.printStackTrace ();} MLWM&cFG
catch(Exception e){e.printStackTrace ();} ;\Y&ce
} T}P".kpbS
!Kj,9NX{U
@I/]D6 ~"
private void processErrorCode(int nErrorCode) "4H +!r}
{ ^Z#W_R\l
System.err.println("Error Code : " + nErrorCode); V<@ o<R
} k"]dK,,
_/!y)&4"
;z:UN}
//停止文件下载 \":m!K;Z
public void siteStop() ^8Q62
{ G *;a^]-
bStop = true; 1ilBz9x*!
for(int i=0;i<nStartPos.length;i++) ;Q[mL(1:
fileSplitterFetch.splitterStop(); Upd3-2kr&J
#KXa&C
;b(p=\i
} ,%Up0Rr,
} MP 2~;T}~
//负责部分文件的抓取 "7V2lu
**FileSplitterFetch.java :8+Nid)
*/ 1/-43B
package NetFox; )ZqJh
#w-xBM @
tAte)/0C
import java.io.*; p)3U7"q
import java.net.*; @u%_1
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glXZZ=j
public class FileSplitterFetch extends Thread { #x3ujJ
F[[TWf/
yH*6@P4:0=
String sURL; //File URL sWblFvHqrU
long nStartPos; //File Snippet Start Position $3uKw!z
long nEndPos; //File Snippet End Position GJp85B!PlO
int nThreadID; //Thread's ID 16i"Yg!*
boolean bDownOver = false; //Downing is over Bw64
boolean bStop = false; //Stop identical HcV"X,7S
FileAccessI fileAccessI = null; //File Access interface (BfgwC)
'@CR\5 @
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *`Yv.=cd
{ R@#G>4
this.sURL = sURL; %ck]S!}6
this.nStartPos = nStart; (S`2[.j
this.nEndPos = nEnd; njnDW~Snb
nThreadID = id; %T9 sz4V
fileAccessI = new FileAccessI(sName,nStartPos);//定位 X2i}vjkY
} L%c0Z@[~
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,qrQ"r9
public void run() 4bJZmUb
{ 0Ir<y
while(nStartPos < nEndPos && !bStop) Z)xaJGbw
{ z.VyRBi0
yxq}QSb \3
mA@Me7m}
try{ [j:[
URL url = new URL(sURL); &0BdUU+:<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D.6,VY H
httpConnection.setRequestProperty("User-Agent","NetFox"); T,OwM\`.X{
String sProperty = "bytes="+nStartPos+"-"; TbF4/T1b
httpConnection.setRequestProperty("RANGE",sProperty); i^!ez5z
Utility.log(sProperty); j]m|7]
e=QK}gzX
~E^,=4
InputStream input = httpConnection.getInputStream(); c9nH}/I_
//logResponseHead(httpConnection); T}=>C+3r
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KyO8A2'U
byte[] b = new byte[1024]; 5+jf/}tA
int nRead; fn/7wO$!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3u\;j; Td!
{ oejfU;+$
nStartPos += fileAccessI.write(b,0,nRead); e~T@~(fft
//if(nThreadID == 1) K!mOr
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cbu@*NzY,
} LR,7,DH$9'
2.X"f
0G2g4DSKD
Utility.log("Thread " + nThreadID + " is over!"); a3>zoN
bDownOver = true; m3g2b _;
//nPos = fileAccessI.write (b,0,nRead); TV}}dw
} M-uMZQe
catch(Exception e){e.printStackTrace ();} *$M'`vj:
} ,[nm_^R*\
} Jj^GWZRu
=)OC|?9C\
fXQiNm[P
//打印回应的头信息 V=:_d,
public void logResponseHead(HttpURLConnection con) Ih[+K#t+E
{ +"g~"<
for(int i=1;;i++) ^5t
{ l48k<
String header=con.getHeaderFieldKey(i); 5ZAb]F90
if(header!=null) @oG)LT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v1.q$ f^(
Utility.log(header+" : "+con.getHeaderField(header)); SgE/!+{
else ?Jtg3AY
break; jec:i-,
} [W,-1.$!dM
} C+MSVc
Y+/lX6'
&VWlt2-R0h
public void splitterStop() m^{ xd2
{ |H ;+1
bStop = true; n`;R pr&
} aP>37s
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ZZ)G5ji
} (5uJZ!m
pyW u9
YbMssd2Yg
/* s([Wn)I
**FileAccess.java R.1Xst &i
*//文件访问(定位，写) Z]-WFU_ N
package NetFox; i.rU&yT%
import java.io.*; 8kW/DcLE
?|t/mo|K?
GF--riyfB
public class FileAccessI implements Serializable{ :LV.G0)#
->yeJTsE9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 hr U :Wr
RandomAccessFile oSavedFile; Xi~9&ed#$i
long nPos; BQjam+u6
$+:(f{Va*
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public FileAccessI() throws IOException }#b %"I0
{ mTEVFm
this("",0); /= ^L iP
} 7>x;B
w4:<fnOM
NdQ%:OKC
public FileAccessI(String sName,long nPos) throws IOException v'nHFC+p
{ Jqg3.2q
oSavedFile = new RandomAccessFile(sName,"rw"); z`'P>.x
this.nPos = nPos; `45d"B I
oSavedFile.seek(nPos); O:u%7V/
} `$9L^Yg,4
YZ[%uArm
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public synchronized int write(byte[] b,int nStart,int nLen) xzK>Xi?
{ l @A"U)A(
int n = -1; U,3d) ]Zy&
try{ @9_)On9hZ
oSavedFile.write(b,nStart,nLen); [s %\.y(q
n = nLen; EVSK8T,
} >q&L/N5
catch(IOException e) 0Uaem
{ ype"7p\
e.printStackTrace (); dP3VJ3+ %
} ?zE<
AJWLEc4XK
36i_D6
return n; !pS~'E&q
} WH;xq^
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n8?KSQy$
} WFpl1O73
q @*UUj@
'Ix5,^M}B
/* Q^q=!/qQ
**SiteInfoBean.java RhyegD
*/ DoTs9w|5
package NetFox; ujNt(7Cz
67,3i~
g` kZT} h
public class SiteInfoBean { &{hc
>VypE8H]x
u-1@~Z
private String sSiteURL; //Site's URL )PHl>0i!
private String sFilePath; //Saved File's Path 1S^'C2/b
private String sFileName; //Saved File's Name NB3/A"}"02
private int nSplitter; //Count of Splited Downloading File `-5cQ2>"
l4DeX\ly7f
|M]sk?"^
public SiteInfoBean() 7:ckq(89
{//nSplitter的缺省值为5 H.)fOctbO
//default value of nSplitter is 5 U=M#41J
this("","","",5); UVnrDhd!0
} Sq.9-h%5
0U9+
"C?:T'dW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G)jG!`I
{ A"`L~|&
sSiteURL= sURL; il=?of\,i
sFilePath = sPath; 2c!h2$w
sFileName = sName; T27:"LVw
this.nSplitter = nSpiltter; XlE$.
5ZZd.9ZgM
xAFek;GY?
} cvn-*Sj
Cl%V^xTb
[))gn
public String getSSiteURL() &f$a1#O}dx
{ p<<6}3~
return sSiteURL; UeFtzty,a
} YmdsI+DbIu
i%#th'C!P
;:-}z.7Y
public void setSSiteURL(String value) ]v/t8`
{ ~oEXM?M
sSiteURL = value; Vj?*=UL
} /W7&U =d9
|p'_k(z}
x(exx )w
public String getSFilePath() l#mqV@?A~
{ _SU,f>
return sFilePath; yz54:q?
} X20<r?^,,
/&y,vkZTT
9aW8wYL~b
public void setSFilePath(String value) >b[4
{ J@=!w[v+
sFilePath = value; g)2m$#T&s
} T\<M?`Y
#c8"
;,[EJR^CI
public String getSFileName() Pl`Bd0
{ W$x K^}
return sFileName; WV9[DFU
} t!+%g) @
7$E2/@f
%3#b6m~
public void setSFileName(String value) CNpCe-%&
{ A5(kOtgiT
sFileName = value; SLbavP#G
} ^hGZVGSv
RXCygPT
K6PC&+x
public int getNSplitter() ^MF=,U'8
{ >?:i6&4o
return nSplitter; +'{:zN5m
} 3RY|l?n>
J:M<9W
FQv02V+&<
public void setNSplitter(int nCount) C5W-B8>
{ OV0cr
nSplitter = nCount; dNS9<8JX
} R[2[[M
} O~c+$(
Rqv+N]
T`0`]z!~
/* Mz%d_
**Utility.java ]xVL11p
*/ cqU$gKT
package NetFox; 1bFEx_
Hf`&&
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public class Utility { J}93u(T5
~h~r]tV*+
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public Utility() `rRg(fCN!M
{ _YD<Q@
+eH=;8
(\AszLW
} iIC9rso"Q1
U iPVZ@?
//线程睡眠 ir1RAmt%
public static void sleep(int nSecond) Jq=>H@il
{ Qcy+ {j]
try{ ;_;H(%uY
Thread.sleep(nSecond); NEjBjLJZ
} QRn:=J%W W
catch(Exception e) 0[3tW[j
{ Hr_x~n=w
e.printStackTrace (); d&3I>E$UP
} hKH Q!`&v
} A`mf 8'nTG
L2Qp6A6S
//日志 b~N|DKj
public static void log(String sMsg) 55)ep
{ xDAA`G
System.err.println(sMsg); {U2|):
} N'q/7jOy
u6CMRZ$
22H=!.DJ
public static void log(int sMsg) S7\jR%pb
{ M4$4D?
System.err.println(sMsg); Kk"B501
} ,YuWz$aF{
} +HVG5l
wNlV_
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/* w2mlqy2L
**TestMethod.java 1QdB`8in
*/ .bl/At3A
package NetFox; ,_7tRkn
r+WPQ`Ar
[zO(V`S2
public class TestMethod { <\#
:8/M6-EK
OW5|oG
public TestMethod() \c`r9H^v{
{ ///xx/weblogic60b2_win.exe Z6HkQ=A64
try{ zz''FmedF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aABE= 9Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q(eQZx{
SiteFileFetch fileFetch = new SiteFileFetch(bean); \6PIw-)
fileFetch.start(); g\mrRZ/?
} SGT-B.
catch(Exception e){e.printStackTrace ();} "}Sid+)<
*/@bNT9BgO
XVK[p=cIL
} c`[uQXv
;Z<*.f'^fc
{b8Y-
public static void main(String[] args) QRc=-Wu_(
{ bJ5z??
new TestMethod(); >w2WyYJYH
} p9bxhnn|
} X2mm'JDwK
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