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)); k*6eZ7
} /2V',0
for(int i=0;i<nEndPos.length-1;i++) Wv/5#_
{ ea}KxLC`,
nEndPos = nStartPos[i+1]; A-!qO|E[-
} R$m?&1K
nEndPos[nEndPos.length-1] = nFileLength; /,%o<Ql9
} vjRD?kF
} x(N}^Hu
X.Y)'qSf
R*G>)YH
//启动子线程 /Z_ [)PTH
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; dY`J,s
for(int i=0;i<nStartPos.length;i++) Ijro;rsEKM
{ PCnJ2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), E1w XG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), kV9NFo22
nStartPos,nEndPos,i); /j\TmcnU^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); V+5 n|L5
fileSplitterFetch.start(); {#Cm> @')
} c0p=/*s(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +NMSvu_?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z'm%3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %--5bwZi
nEndPos = " + nFileLength); 4\WkXwoqQO
// fileSplitterFetch[nPos.length-1].start(); -^Va]Lk
<Py/uF|
D5vtZu!"
//等待子线程结束 CnA)>4E*'
//int count = 0; emIbGkH
//是否结束while循环 b>._ r&.
boolean breakWhile = false; n:)Y'52}
{X"]92+
x)mC^
while(!bStop) 9Bw5 t@
{ w~?eX/;
write_nPos(); r_RTtS#
Utility.sleep(500); . L%@/(r
breakWhile = true; ToM*tXj
yvwcXNXR@
o[6"XJ
for(int i=0;i<nStartPos.length;i++) XYTcG;_z
{ HhH'\-[t
if(!fileSplitterFetch.bDownOver) D+PUi!
{ Jl,x~d
breakWhile = false; XKIJ6M~5k
break; DdBrJx
} >G7U7R}R
} S6Pb V}
if(breakWhile) ..mz!:Zs0
break; _J;a[Ky+[
Hf|:A(vCx
9DE)5/c`v
//count++; swbD q
//if(count>4) YHAg4eb8
// siteStop(); P*sCrGO%
} Sd11ZC6
e 3oIoj4o
IvH+94[)
System.err.println("文件下载结束！"); jK1! \j
} El}z^e
catch(Exception e){e.printStackTrace ();} DL{a8t1L
} F\<i>LWT'
Sp:de,9@
j`lK}
//获得文件长度 _zwuK1e
public long getFileSize() [}3Y1t{G
{ .1}(Bywm5
int nFileLength = -1; ?!Gt. fb
try{ 7|Y8^T s
URL url = new URL(siteInfoBean.getSSiteURL()); t/(j8w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )}5rs
httpConnection.setRequestProperty("User-Agent","NetFox"); b7mP~]V
&T}e93]
}$U6lh/Ep
int responseCode=httpConnection.getResponseCode(); =p$Wo
if(responseCode>=400) 1t'\!
{ "rJL ^ \r
processErrorCode(responseCode); ')<$AMy1
return -2; //-2 represent access is error 5o#8DIal
} _;W|iUreb
}qPo%T
]uf_"D
String sHeader; P*]g*&*Y +
GjBQxn
R?I3xb
for(int i=1;;i++) VTa8.(i6v
{ S0yT%V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uM#/
//Utility.log(in.readLine()); mQJGKh&Pk
sHeader=httpConnection.getHeaderFieldKey(i); dGjvSK<1@
if(sHeader!=null) XwMC/]lK<
{ d?.x./1[qi
if(sHeader.equals("Content-Length")) HR
{ ysPW<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 24fWj?A|^
break; { q<l]jn9
} f^ qQ5N
} TmiQq'm[b
else plAt +*&
break; cPSu!u}D
} ?9A[;j|a0
} y5}|Y{5
catch(IOException e){e.printStackTrace ();} HDOaN
catch(Exception e){e.printStackTrace ();} HY:n{=o
ok'1
f[D#QC
Utility.log(nFileLength); nceF4Ty
^xrR3m*d
&-A7%"
return nFileLength; duCm+4,.
} l?~h_8&fT
6G],t)<A'-
Hn)=:lI
//保存下载信息（文件指针位置） RZjR d
private void write_nPos() sMK/l @7
{ Ql 1# l:Q
try{ Mv3Ch'X[
output = new DataOutputStream(new FileOutputStream(tmpFile)); @@QU"8q
output.writeInt(nStartPos.length); <[bDNe["?
for(int i=0;i<nStartPos.length;i++) I\_R& v
{ ;z#9>99rH
// output.writeLong(nPos); YX(%jcj*
output.writeLong(fileSplitterFetch.nStartPos); ~S9nLb:O{
output.writeLong(fileSplitterFetch.nEndPos); C Qebb:y
} FKP^f\!M
output.close(); j&9~OXYv
} )d~Mag+
catch(IOException e){e.printStackTrace ();} *?S\0a'W@
catch(Exception e){e.printStackTrace ();} $.kYAsZts
} gFH_^~7i8p
{ig@Iy~DT
|j<'[gB\p
//读取保存的下载信息（文件指针位置） =Ao;[j)*!
private void read_nPos() I~I%z'"RQd
{ F 7=-k/k
try{ dGg+[?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); s0u$DM2
int nCount = input.readInt(); 6-~
nStartPos = new long[nCount]; "?!IPX2\S
nEndPos = new long[nCount]; b8Qm4b?:4
for(int i=0;i<nStartPos.length;i++) tj0vB]c
{ 6yU~^))bx
nStartPos = input.readLong(); #LZ`kSlv4
nEndPos = input.readLong(); Jc+U$h4
} 3^\y>
input.close(); x9=lN^/4
} -:QyWw/d
catch(IOException e){e.printStackTrace ();} `#V"@Go
catch(Exception e){e.printStackTrace ();} *VUXw@
} jL# akV
*=8)]_=f
+2?[=g4;}
private void processErrorCode(int nErrorCode) _:z~P<%s
{ 7]Egu D4
System.err.println("Error Code : " + nErrorCode); ! 9e>J
} {2nXItso
:A$6Y*s\
1\2 m'o
//停止文件下载 ]kPco4
public void siteStop() Dj|S
{ `C1LR,J
bStop = true; (R,eWWF8~
for(int i=0;i<nStartPos.length;i++) ?OSd8E+itM
fileSplitterFetch.splitterStop(); i0P+,U
"YBA$ef$
,ZSuo4
} r{btBv
} V6L_aee}CK
//负责部分文件的抓取 s-*XAnot
**FileSplitterFetch.java >dM'UpN@
*/ Wwz>tE
package NetFox; ps]6,@uyB
3B0%:Jj
5IepVS(>?v
import java.io.*; g^idS:GtX5
import java.net.*; ;9~z_orNQZ
}yw\+fc
{*2A%}S
public class FileSplitterFetch extends Thread { p#&6Ed*V
'D4NPG`z
8WH>
String sURL; //File URL KQqlM
long nStartPos; //File Snippet Start Position G`n-WP
long nEndPos; //File Snippet End Position `'93J wYb
int nThreadID; //Thread's ID /\9Kr;@vk
boolean bDownOver = false; //Downing is over %guot~S|
boolean bStop = false; //Stop identical YP7<j*s8
FileAccessI fileAccessI = null; //File Access interface z7CYYU?
#wo_
oeIS&O.K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M]W4S4&Y=
{ YcI]_[
this.sURL = sURL; c]9OP9F
this.nStartPos = nStart; 1vThb
this.nEndPos = nEnd; &qr7yyY
nThreadID = id; s^U^n//
fileAccessI = new FileAccessI(sName,nStartPos);//定位 |oM6(px
} {r"s.|n
_w26iCnB{
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public void run() 1~*_H_Q't
{ r}991O<
while(nStartPos < nEndPos && !bStop) sqy5rug
{ %6n;B|!
pp:+SoyN
5mV'k"Om#"
try{ >[p+L='
URL url = new URL(sURL); *-n$n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >A)he!I
httpConnection.setRequestProperty("User-Agent","NetFox"); ua{eri[
String sProperty = "bytes="+nStartPos+"-"; %H@fVWe2wT
httpConnection.setRequestProperty("RANGE",sProperty); }X$>84s>[P
Utility.log(sProperty); AkF1Hj
%8ul}}d9
R6!3Y/Q@
InputStream input = httpConnection.getInputStream(); 2@H~nw 0
//logResponseHead(httpConnection); $OJ*Kul
^,X+ n5q;m
HCP Be2
byte[] b = new byte[1024]; [W;14BD7
int nRead; %!q(zql
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $lv g.u
{ V}(%2W5X+
nStartPos += fileAccessI.write(b,0,nRead); M:x8]TA
//if(nThreadID == 1) jJf|Ok:G{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); DJbj@ 2W[
} \h yTcFb
koUH>J:
E>ev/6ox
Utility.log("Thread " + nThreadID + " is over!"); * T-XslI
bDownOver = true; -,rl[1ZYZ
//nPos = fileAccessI.write (b,0,nRead); kTzZj|l^\
} R38 w!6{
catch(Exception e){e.printStackTrace ();} n;MoMGnPh,
} Y8P
} $yt|nO
9uq| VU5
`wq\K8v
//打印回应的头信息 7W>T= @
public void logResponseHead(HttpURLConnection con) Op|Be
{ snK/,lm.
for(int i=1;;i++) 8xNKVj)@
{ mr;WxxO5
String header=con.getHeaderFieldKey(i); A[b'MNsv
if(header!=null) x&f?c=\F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >1r>cZn
Utility.log(header+" : "+con.getHeaderField(header)); 7#RW4ZM
else Ghj6&K%b0
break; ,^'Y7"
} 5/(Dh![l
} wCdUYgsPT"
:s4CWEd
A*$vk2VWw
public void splitterStop() wM|-u/9+
{ UVUHLu|^
bStop = true; `0so)2ty+
} B}3s=+L@8
@}[)uH
u%T.XgY=j
} s_]rje8`
F'"-4YV>&
bkY7]'.bz&
/* z*R"917
**FileAccess.java Lrk^<:8;
*//文件访问(定位，写) Xc@4(Nyp
package NetFox; |GMK@Q'0:
import java.io.*; l@^RbF['
2Gj&7A3b
m7eO T
public class FileAccessI implements Serializable{ Q8P;AN_JS
!?KY;3L:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yyXJ_B
RandomAccessFile oSavedFile; HezCRtxRcc
long nPos; YX~H!6l
2;q6~Y,
D6 M:pIN*
public FileAccessI() throws IOException f[X>?{q
{ 10a=[\ Q
this("",0); F6fm{
} 2\7]EW
(;s\Ip0
r[hfN2,#
public FileAccessI(String sName,long nPos) throws IOException alq>|,\x
{ I5-/KVWb
oSavedFile = new RandomAccessFile(sName,"rw"); C[[z3tn
this.nPos = nPos; q-uYfXZ{j
oSavedFile.seek(nPos); y(q1~73s
} ]CTu|
#-@dc
[@/G?sAQm\
public synchronized int write(byte[] b,int nStart,int nLen) 04,]upC${W
{ jdhhvoQ
int n = -1; v!W,h2:J
try{ ;ymUMQ%;/
oSavedFile.write(b,nStart,nLen); y<5s)OehG
n = nLen; uD+;5S]us
} V57^0^Zp`
catch(IOException e) MRiETd"
{ ysSEgC3
e.printStackTrace (); Q:%gJ6pa
} Zaq:l[%
aE:fMDS|x
&gq\e^0CRZ
return n; 1W;+hXx
} Ex~OT
M T{^=F ]
($ae n
} zRu}lJ1#W$
b7=]"|c$@
P$qIB[Xi
/* vH`u
**SiteInfoBean.java Um*{~=;u
*/ Z EG
package NetFox; g6nBu
(/Nw
K+n6.BzW
public class SiteInfoBean { f\Pd#$3
Rh:\/31~
03#r F@e
private String sSiteURL; //Site's URL E4WoKuE1$
private String sFilePath; //Saved File's Path @!K)(B;A0b
private String sFileName; //Saved File's Name A/GEDG ?
private int nSplitter; //Count of Splited Downloading File ]x~H"<V
QHA<7Wg
xH*OEzN
public SiteInfoBean() Ff.gRx
{//nSplitter的缺省值为5 /\C9FGS
//default value of nSplitter is 5 vk{dL'
this("","","",5); [ UQzCqV
} *-gS u
+
tV%M2DxS
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }`>u+iH#a
{ <Y9ps`{}:
sSiteURL= sURL; wxF9lZz
sFilePath = sPath; Rh~<#"G]
sFileName = sName; w!tQU9+*
this.nSplitter = nSpiltter; 5q" ;R$+j
:0V<
0hCJovSG%
} *p+%&z_<
skr^m%W
670g|&v.
public String getSSiteURL() Pgb<;c:4
{ 1P&c:n
return sSiteURL; R$NH [Tz
} WCU[]A
Wrt3p-N"D
HlLF<k~}
public void setSSiteURL(String value) .~C*7_
{ |VTm5.23
sSiteURL = value; .}2^YOmd
} C$Ldz=d
|f.=Y~aY
Trm)7B*
public String getSFilePath() ?GX5Pvg
{ |Q.t]TR'P
return sFilePath; w#]%I+
} mG\,T3/*
hyFq>XFo
#;>J<>
public void setSFilePath(String value) uB0/H=<H
{ y~''r%]
sFilePath = value; NSj}?hz
} g,mcxXO
wbVM'E/&
Z=4Krfn
public String getSFileName() ,.G6c=pZ
{ `dMl5b
return sFileName; cKdy)T%;
} ~cQP4 kBD]
i$$\}2m{L
>\[sNCkf
public void setSFileName(String value) ^o65sM
{ I3p ~pt2
sFileName = value; 6D@tCmmq
} 'd(OFE-hn
KhYGiVA
cBiv=!n
public int getNSplitter() Ond"Eq=r
{ R2Lq,(@-
return nSplitter; 9kWyO:a_(
} f!eC|:D
pNCk~OM
!JJCG
public void setNSplitter(int nCount) ey@y?X=
{ 2j*\n|"}{
nSplitter = nCount; u3w `(3{<
} :/K 'P`JaL
} Ds$FO}KD{
}|&M@Up
Y?R;Y:u3Z
/* p;U[cGHC
**Utility.java ycIT=AFYqd
*/ @| qnD
package NetFox; `N;u#z
L*11hyyk
{>pB
public class Utility { O=G2bdY{,
uFW4A
rmk'{"
public Utility() -|:7<$2#I
{ <~<I K=n
SG$/v
kT[]^Jtc
} Y6W3WPs(
rM/*_0[`d
//线程睡眠 KSMe#Qnw
public static void sleep(int nSecond) 4cTJ$" v
{ 0`3ey*
try{ x.<^L] "
Thread.sleep(nSecond); 0[x?Q[~S_0
} 8HxB\ !0F?
catch(Exception e) t> -cTQm
{ HRC5z<k%
e.printStackTrace (); gXE'3
} >rB7ms/@E
} f8B*D4R}
XK{`x<
//日志 [`yiD>
public static void log(String sMsg) RT F9;]Ti
{ Z[slN5]([
System.err.println(sMsg); 1Hy
} tt6ElP|D
2sk^A ly
Cx} Yp-
public static void log(int sMsg) _Oh;._PS
{ _|g(BK2}
System.err.println(sMsg); Xa Yx avq
} >OBuHqC
} U3&*,xeU@H
I^qk`5w
/1gKc}rB2
/* 7=6p
**TestMethod.java VQ$=F8ivG
*/ mdoy1a
package NetFox; D-8%lGS
ouPwhB,bg
~i=/@;wRp
public class TestMethod { Q{0-pHr}
ZL+{?1&-
Wu2#r\
public TestMethod() T=A7f6`
{ ///xx/weblogic60b2_win.exe K/, B
try{ J3}^\k=p"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +pnT6kU|
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); nv2Y6e}dG
SiteFileFetch fileFetch = new SiteFileFetch(bean); mO?G[?*\
fileFetch.start(); wGBQ.Ve[
} '.#KkvE##
catch(Exception e){e.printStackTrace ();} i('z~
a+{YTR>0m
(|I0C 'Ki
} ;^=eiurv
bXQ(6P
{MO`0n; rt
public static void main(String[] args) [f:>tRdH
{ qF%wl
new TestMethod(); &bRmr/D
} ^8 AV#a
} 'i%Azzv
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