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)); t)KPp|&
} nqrDT1b**
for(int i=0;i<nEndPos.length-1;i++) shD+eHo$
{ dt0T t
nEndPos = nStartPos[i+1]; 4':MI|/my_
} 8'n#O>V@
nEndPos[nEndPos.length-1] = nFileLength; 0xLkyt0
} m+p4Mc%u
} y]w )`}Ax
~PCTLP~zI
mcCB7<. e
//启动子线程 X:DMT>5k
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @\+%GDv
for(int i=0;i<nStartPos.length;i++) y _6r/z^
{ ,Io0ZE>`V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), =1eV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $vz_%Y
nStartPos,nEndPos,i); N=.}h\{0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W%=Zdm rv
fileSplitterFetch.start(); &:-GI)[o
} 2lF WW(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zI(xSX@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); wE)] ah:
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kja4!_d
nEndPos = " + nFileLength); *q+oeAYX
// fileSplitterFetch[nPos.length-1].start(); `Yg7,{A\J
uQO(?nCi
D\@e{.$MZ|
//等待子线程结束 ux%&lff
//int count = 0; ex{)mE4Cd
//是否结束while循环 'W}~)+zK
boolean breakWhile = false; ^ sS>Mts
4fZY8
o7m99(
while(!bStop) v`@5enr
{ /j`i/Ha1
write_nPos(); xV"6d{+
Utility.sleep(500); !IfI-Q
breakWhile = true; -7&^jP\,
M-{b
(N)r#"FV
for(int i=0;i<nStartPos.length;i++) #(m`2Z`H
{ 38Bnf
if(!fileSplitterFetch.bDownOver) +8L(pMI4
{ xgZV0!%
breakWhile = false; Z&AHM &,yj
break; em f0sL
} t-3v1cv"
} }|w=7^1z
if(breakWhile) W@R$'r,@O
break; c#]'#+aH
Ukk-(gjX
,-w-su=J_
//count++; w`H.ey
//if(count>4) }CB=c]p
// siteStop(); s!8J.hD'I
} [lDt0l5^
I!C(K^
S!`4Bl
System.err.println("文件下载结束！"); L%c]%3A
} sR7{i
catch(Exception e){e.printStackTrace ();} 'sT}DX(7M
} N7RG5?
7Va#{Y;Zy
J4Q)`Y\~
//获得文件长度 ,H#qgnp
public long getFileSize() W TXD4}
{ Z~-T0Ab-
int nFileLength = -1; O+{pF.P#V
try{ } kh/mq
URL url = new URL(siteInfoBean.getSSiteURL()); ^C,/T2>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Knw'h;,[
httpConnection.setRequestProperty("User-Agent","NetFox"); Skr\a\ J
`JY>v io
NIWI6qCw
int responseCode=httpConnection.getResponseCode(); rw=UK`
if(responseCode>=400) -Y 6.?z
{ $BR=IYby
processErrorCode(responseCode); 5CRc]Q#@
return -2; //-2 represent access is error 3[|:sa8?s
} Xn ZX *Y]"
@^XkU(m
$Z(g=nS>
String sHeader; k^'d@1z;C
C-:SQf
0$F _hZU
for(int i=1;;i++) 3-_U-:2"
{ "t%1@b*u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xi1N? pP
//Utility.log(in.readLine()); 1K*f4BnDr~
sHeader=httpConnection.getHeaderFieldKey(i); 5u u2 _B_L
if(sHeader!=null) \/x)BE,
{ mKf>6/s{c
if(sHeader.equals("Content-Length")) p0y0T|H^
{ cV=_GE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); gqJEJ~
break; g.`t!6Hc
} hI>rtaY_
} 3q.[-.q
else xJF6l!`
break; b/n8UxA
} jN'fm
} zoJkDr=jn
catch(IOException e){e.printStackTrace ();} :zn ?<(sQ
catch(Exception e){e.printStackTrace ();} utm+\/
beHCEwh
L9unhx
Utility.log(nFileLength); q:~`7I
ncw?;
\Zz= 4 j
return nFileLength; Y4~wNs6
} sWZtbW;)
$vbAcWj
W|-N>,G
//保存下载信息（文件指针位置） XpAq=p0;
private void write_nPos() Eztz~oFo
{ B 1ZHV^
try{ { d2f)ra.
output = new DataOutputStream(new FileOutputStream(tmpFile)); '*LN)E>d
output.writeInt(nStartPos.length); Ag-?6v
for(int i=0;i<nStartPos.length;i++) .L(j@I t
{ }$k`[ivBx(
// output.writeLong(nPos); J&U0y
output.writeLong(fileSplitterFetch.nStartPos); FnQ_=b
output.writeLong(fileSplitterFetch.nEndPos); @01D1A
} /&!d
output.close(); 3f2Hjk7,d
} /%q9hI
catch(IOException e){e.printStackTrace ();} )6R#k8'ERr
catch(Exception e){e.printStackTrace ();} =|JIY
} F+y`4>x
T#_n-b>
46?F+,Rzl
//读取保存的下载信息（文件指针位置） Lvj5<4h;
private void read_nPos() |KrG3-i3X
{ )w 8lusa
try{ z9kX`M+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L9YwOSb.
int nCount = input.readInt(); *=0r>]
nStartPos = new long[nCount]; u+gXBU
nEndPos = new long[nCount]; Q]g4gj
for(int i=0;i<nStartPos.length;i++) ^FMa8;'o
{ ]3y5b9DuW
nStartPos = input.readLong(); O2/w:zOg'
nEndPos = input.readLong(); UoS;!}l
} &@iF!D\u
input.close(); +G[HZ,FL
} Y&!]I84]
catch(IOException e){e.printStackTrace ();} ]j$p_s>
catch(Exception e){e.printStackTrace ();} w~KBk)!*
} PXu<4VF
:E&T}RN
'=5_u
private void processErrorCode(int nErrorCode) )"Br,uIv:/
{ tKsM}+fq
System.err.println("Error Code : " + nErrorCode); Tocdh.H|
} %s :
p{svXP K
`0XbV A
//停止文件下载 cBF%])!
public void siteStop() K}/`YDu
{ f=O>\
bStop = true; u2O^3rG-
for(int i=0;i<nStartPos.length;i++) BOQV X&g%
fileSplitterFetch.splitterStop(); mFoK76
a&aIkD
G/3lX^Z>
} R/cq00g
} 2pNJWYW"
//负责部分文件的抓取 )0d".Q|v4
**FileSplitterFetch.java E/P53CD
*/ K}3"KC
package NetFox; F8;4Oj
]%8;c
4m!3P"$
import java.io.*; *xTquV$
import java.net.*; 7.rZ%1N
X&oy.Roo
/r@
public class FileSplitterFetch extends Thread { @5VZ
[\n.[4gq"
}gRLW2&mR>
String sURL; //File URL Y8'_5?+ 0
long nStartPos; //File Snippet Start Position t U=b~
long nEndPos; //File Snippet End Position >,vW
int nThreadID; //Thread's ID tS|zf,7
boolean bDownOver = false; //Downing is over -+@~*$ d
boolean bStop = false; //Stop identical > 0)`uJ
FileAccessI fileAccessI = null; //File Access interface d6 EJn/
.T wF]v
bJ!f,a'/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `^k<.O
{ &n kGdHX/a
this.sURL = sURL; Eakjsk
this.nStartPos = nStart; "dOY_@kg
this.nEndPos = nEnd; !O_^Rn+<2
nThreadID = id; J uKaRR~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "fd=(& M*l
} GhA~PjZS
2;r^~:
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public void run() 5z]KkPQ
{ I3b-uEHev
while(nStartPos < nEndPos && !bStop) ]r5Xp#q2
{ HV(*6b@
0Hf-~6
wb"t:(>&
try{ o;/F=Zp
URL url = new URL(sURL); R$`T"C"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S]@iS[|?
httpConnection.setRequestProperty("User-Agent","NetFox"); scwlW b<N
String sProperty = "bytes="+nStartPos+"-"; I65GUX#DV
httpConnection.setRequestProperty("RANGE",sProperty); .W:], 5e
Utility.log(sProperty); RlIqH;n
:PkSX*E[q
( h,F{7
InputStream input = httpConnection.getInputStream(); #2,L)E\G8e
//logResponseHead(httpConnection); ]2 N';(R
1h{_v!X
||NCVGJG
byte[] b = new byte[1024]; `XY[HK
int nRead; H[U*' 2TJ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y+h=x4t
{ H-lRgJdc
nStartPos += fileAccessI.write(b,0,nRead); oWOZ0]H1
//if(nThreadID == 1) kp"cHJNx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6h8NrjX
} <{j9|mt
EB,>k1IJ
6Wp:W1E{`
Utility.log("Thread " + nThreadID + " is over!"); "WL
bDownOver = true; S_=uv)%a
//nPos = fileAccessI.write (b,0,nRead); L.[2lQ
} ](pD<FfS]'
catch(Exception e){e.printStackTrace ();} B[h9epU]K
} PX'%)5:q;i
} A+&Va\|x
" OtLJ
H*IoJL6
//打印回应的头信息 /8R1$7
public void logResponseHead(HttpURLConnection con) A 78{b^0*
{ t&]IgF
for(int i=1;;i++) I+SL0
{ ( d.i np(
String header=con.getHeaderFieldKey(i); >LSA?dy!?
if(header!=null) ap!<8N
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 0fNBy^(K
Utility.log(header+" : "+con.getHeaderField(header)); j!/(9*\
else ;RI,zQ
break; ebchHnOd
} /uVB[Tk^
} q ^?{6}sy
@lI/g
EUgs2Fsb3
public void splitterStop() 60Z)AQs;+J
{ S3m+(N"&
bStop = true; Ho/5e*X
} sQvEUqy9
X}Lp!.i9o
y[vjqfdmU
} P\R3/g
h)rHf3:
aw`mB,5U
/* ]iPdAwc.1
**FileAccess.java uIu0"pv`x
*//文件访问(定位，写) $f%_ 4 =
package NetFox; = ~yh[@R)
import java.io.*; %`~8j H@
K;Ktx>Z/
"o1/gV
public class FileAccessI implements Serializable{ zy.Ok 49
X qh+
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 E5rNC/Ul$$
RandomAccessFile oSavedFile; `]Xbw^Y'x
long nPos; C$_H)I
@!-= :<h
gaJS6*P#
public FileAccessI() throws IOException &EMm<(.]a
{ X,p&S^
this("",0); tY7u\Y;^
} .{6TX"M
:%Bo)0a9
2/GH5b(
public FileAccessI(String sName,long nPos) throws IOException niFjsTA.Z
{ 2oNlQiE_
oSavedFile = new RandomAccessFile(sName,"rw"); Z/64E^
this.nPos = nPos; cu Nwv(P
oSavedFile.seek(nPos); I(2ID +
} )/BKN`,
X%;,r 2g
3M^ /
public synchronized int write(byte[] b,int nStart,int nLen) ?)9 6YX'
{ 5ewQjwW0
int n = -1; > vgqf>)kk
try{ f1JvP\I0Q
oSavedFile.write(b,nStart,nLen); Bq'hk<ns[
n = nLen; xa K:@/
} GU=h2LSi]
catch(IOException e) &vLZj
{ B64%| S
e.printStackTrace (); ~ejHA~QC
} 7%aB>uA
/H\ZCIu/7
:^l`m9
return n; 1y>P<[
} !Qn:PSk
Q}G
w2 CgEJ%
} c!s{QWd%
B~z& "`
rGx1>xd(k
/* u U\UULH0
**SiteInfoBean.java bE0cW'6r
*/ )5bhyzSZI
package NetFox; jo+T!CUM'
='>k|s:
89~)nV)
public class SiteInfoBean { 7HFw*;
he 9qWL&^G
KrG$W/<tg
private String sSiteURL; //Site's URL >a Q;8
private String sFilePath; //Saved File's Path =TU"B-*
private String sFileName; //Saved File's Name UtY<R
private int nSplitter; //Count of Splited Downloading File XVE(p3-
E+csK*A7
jR*1%.Ng
public SiteInfoBean() pM.>u/=X
{//nSplitter的缺省值为5 H2[S]`?
//default value of nSplitter is 5 J/WPffqD
this("","","",5); F~z4T/TN%G
} 9qW^@5 m
kC6J@t)
,}F{V>dhn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /zM
{ 8+Oyhd*|
sSiteURL= sURL; rWAJL9M
sFilePath = sPath; %E,s*=j
sFileName = sName; @<r;>G
this.nSplitter = nSpiltter; Cz8=G;\
02SFFqm
J_<ENs-
} 4ijoAW3A^
/a(xUm@.
_T)dmhG
public String getSSiteURL() UcKpid
{ -}4<P}.5T
return sSiteURL; +)dQd T0Fq
} <Pg4>
xOp8[6Ga'
T\NvN&h-
public void setSSiteURL(String value) 0_J<=T?\"s
{ #0zMPh /U}
sSiteURL = value; IJhJfr0)Oo
} 7&DhEI ^
!:'%'@uc
tn>$5}^;
public String getSFilePath() :RBp
{ _ )b:F=4j
return sFilePath; ]_G!(`Udh
} 0sD"Hu
Xb@lKX5Re
Ml@,xJ/aia
public void setSFilePath(String value) \=P+]9
{ /J")S?. [u
sFilePath = value; / q*n*j
} U ]Ek5p
HTA@en[5
]2`PS<a2
public String getSFileName() X"0n*UTF,
{ vN=e1\
return sFileName; 6nRXRO
} ?`#)JG,A7
kmXpj3
Y]!8Ymuww@
public void setSFileName(String value) !$ItBn/_
{ $iu{u|VSu
sFileName = value; E2+x?Sc+
} +nU"P
+n_`*@SE
wcDHx#~
public int getNSplitter() |E/U(VS3l~
{ d}#G~O+y3v
return nSplitter; 4Y2l]86
} NZ`Mq
mMo<C_~w&
RRR'azT
public void setNSplitter(int nCount) ME4Ir
{ j{PuZ^v1
nSplitter = nCount; v,qK=]ty
} 'Pyeb`AXE9
} BIyNiol$AJ
<4V]>[{W
$C@v
/* AT.WXP0$A
**Utility.java G4DuqN~2m
*/ `uK_}Vy_
package NetFox; (9R;a np
nu|paA
3N%%69JN)
public class Utility { Q?]307g7
V0yQ
N#<h/
public Utility() e]N?{s
{ tu(k"'aJ
/Hxz@=LC1
zSs5F_
} TK"!z(p
r2,AZ+4FP
//线程睡眠 (W.euQy
public static void sleep(int nSecond) 'J*)o<%
{ w783e
try{ '&_<!Nv3
Thread.sleep(nSecond); D#lx&J.s
} Gp6|0:2,L~
catch(Exception e) $'M:H_T
{ &gIDcZ
e.printStackTrace (); C/nzlp~
} K&{*sa r
} 3)SO-Bz\
W/Rb7q4v
//日志 S(;3gQ77
public static void log(String sMsg) P<@Yux#
{ ==d@0`
System.err.println(sMsg); C+/D!ZH%P
} {eR,a-D!7
DkO>?n:-C
x@EEMO1_"
public static void log(int sMsg) ~;aSE
{ -#XNZy!//
System.err.println(sMsg); [&mYW.O<
} <{\UE~
} 0q%=Vs~@g
<fY<.X
8e_ITqV%
/* V+A1O k)
**TestMethod.java <L+D
*/ 'WH@Zk/l
package NetFox; |0Kj0u8T
*GsrG*OM*D
F*WWv&\X
public class TestMethod { l\8l.xP
E.Hw|y0_(|
D_E^%Ea&`
public TestMethod() @vf{_g<
{ ///xx/weblogic60b2_win.exe 7{oG4X!
try{ `m5cU*@D
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); rn1FCJ<;H
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *(&,&$1K
SiteFileFetch fileFetch = new SiteFileFetch(bean); z41 p$
fileFetch.start(); &o/&T{t}
} CORNN8=k
catch(Exception e){e.printStackTrace ();} /Ny/%[cu
Py 8o8*H
5v8&C2Jy@
} 1N<)lZl)
^r=#HQGt
N i^pP@('
public static void main(String[] args) 6YT*=\KT
{ )|/t}|DIx
new TestMethod(); hD\C[C,
} {rOz[E9vm
} z'r.LBnh
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