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)); B., BP
} 3Co1bY:
for(int i=0;i<nEndPos.length-1;i++) YI> xxWA
{ LU`)
nEndPos = nStartPos[i+1]; w"#rwV&
} ]gm3|-EiY
nEndPos[nEndPos.length-1] = nFileLength; G"kX#k0S
} Q~k|lTf
} aNQ(xiskb
rKdsVW
k B4Fz
//启动子线程 8Gy*BpmJn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;l `Ufx
for(int i=0;i<nStartPos.length;i++) @ 'N$5
{ rOO10g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), bFlI:R&<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), e7\gd\
nStartPos,nEndPos,i); p=Leoc1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UvB\kIH
fileSplitterFetch.start(); ]#rV]As
} E}a.qM'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 4^4T#f2=e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); B4+c3M\$V
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", pv&iJ7RN
nEndPos = " + nFileLength); es\ qnq
// fileSplitterFetch[nPos.length-1].start(); |TkicgeS
@PhAg
?hR0 MnP
//等待子线程结束 8m `Y
//int count = 0; aG4 ^xOD
//是否结束while循环 \Cin%S.C
boolean breakWhile = false; "wKJ8
@H(7Mt
QtWe,+WWV
while(!bStop) #N64ZXz_
{ Aw4)=-LKO
write_nPos(); x_?K6[G&}
Utility.sleep(500); ~i'!;'-_}
breakWhile = true; ="%887e
U2vb&Qu/
fb^R3wd$ff
for(int i=0;i<nStartPos.length;i++) nA.U'=`
{ 4e; le&
if(!fileSplitterFetch.bDownOver) _%B,^0;C
{ 3DB= Xh
breakWhile = false; )hoVB
break; W_Y56@7e
} $vYy19z
} a>,_o(]cW
if(breakWhile) >uQjygjj
break; *ezft&{)`
{)!ua7GF0H
5nceOG8
//count++; {.o4U0+
//if(count>4) >c5
// siteStop(); ^gpd '*b
} xS+xUi
eoQt87VCU
^nOh8L;
System.err.println("文件下载结束！"); p} eO
} P*PJ
catch(Exception e){e.printStackTrace ();} \VW":+
} g/P1lQ)
*`/4KMrq
\9od*y
//获得文件长度 b'R]DS{8
public long getFileSize() .W2w/RayC
{ \:q@I]2
int nFileLength = -1; Dvl\o;
try{ Nt?=0X|M
URL url = new URL(siteInfoBean.getSSiteURL()); r;H#cMj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `022gHYv
httpConnection.setRequestProperty("User-Agent","NetFox"); _,UYbD\[J}
6U%d3"T
1<lfo^B
int responseCode=httpConnection.getResponseCode(); 2\+N<-(F5
if(responseCode>=400) 2.v`J=R
{ $M4_"!
processErrorCode(responseCode); 2_?VR~mA#
return -2; //-2 represent access is error }XpZgd$
} ,+gtr.
K]7[|qf&
r~fnK%|
String sHeader; )qFqf<:yc
*p0n^XZ% ?
8. +f@wv
for(int i=1;;i++) N}{V*H^0QU
{ EBQ_c@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .N\t3\9}
//Utility.log(in.readLine()); 7X>@r"9<
sHeader=httpConnection.getHeaderFieldKey(i); X`eX+9
if(sHeader!=null) dBN:
{ dpt P(H
if(sHeader.equals("Content-Length")) (r}StR+
{ \RFA?PuY
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /;21?o
break; &f?JtpB
} NxK.q)tj6
} rfSEL 57'
else 29|nt1Z
break; L/vw7XNrX
} N#R8ez`
} GU Mf}y
catch(IOException e){e.printStackTrace ();} 9]tW;?
catch(Exception e){e.printStackTrace ();} M.)z;[3O
$~ d6KFT
wXBd"]G)C
Utility.log(nFileLength); CR#-!_=4
Z7e"4wA
AAB_Ytf
return nFileLength; ,MHF
} o`'4EVw*
I\j-
Zny9TP
//保存下载信息（文件指针位置） {%,4P_m
private void write_nPos() PtL8Kd0`C
{ i-dosY`81
try{ uLI;_,/:
output = new DataOutputStream(new FileOutputStream(tmpFile)); JZ-64OT
output.writeInt(nStartPos.length); ?"?AH/ED
for(int i=0;i<nStartPos.length;i++) 'C:i5?zh(q
{ Rx.5;2m
// output.writeLong(nPos); h_\W7xt
output.writeLong(fileSplitterFetch.nStartPos); Lc-WfzT
output.writeLong(fileSplitterFetch.nEndPos); &rG]]IO
} YuzVh9jTI
output.close(); {\LLiU}MJC
} @|'9nPern
catch(IOException e){e.printStackTrace ();} kKC] n
catch(Exception e){e.printStackTrace ();} Sb)}
} {sq:vu@NC
a/%qn-i|p
s,Fts3+
//读取保存的下载信息（文件指针位置） $V/Ke
private void read_nPos() b1."mT!p
{ wW<u)|>ye
try{ uX1{K%^<TW
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ,eqRI>,\
int nCount = input.readInt(); X?`mYoe
nStartPos = new long[nCount]; Ggv*EsN/cC
nEndPos = new long[nCount]; %Z*)<[cIE0
for(int i=0;i<nStartPos.length;i++) ;oVOq$ql
{ n \&H~0X
nStartPos = input.readLong(); wg:\$_Og
nEndPos = input.readLong(); v9t'CMU
} sULsUt#
input.close(); "`Xbi/i
} YNp-A.o W@
catch(IOException e){e.printStackTrace ();} V%zo[A
catch(Exception e){e.printStackTrace ();} >+:cTQ|q
} ##1/{9ywy
,hT**(W
xz+;1JAL3
private void processErrorCode(int nErrorCode) {q~N$"#
{ tejpY
System.err.println("Error Code : " + nErrorCode); 'Ir
} (4rHy*6
KyqP@ {
AF{@lDa1h
//停止文件下载 RyWfoLc
public void siteStop() YnCuF0>
{ lfR}cx
bStop = true; `sd H q
for(int i=0;i<nStartPos.length;i++) V*@&<x"E
fileSplitterFetch.splitterStop(); ,1vFX$
vEt+^3=
7p{uRSE4._
} OO,%zwgt
} #Ny+6XM
//负责部分文件的抓取 ;9Wimf]G,E
**FileSplitterFetch.java cBCC/n
*/ %8P6l D
package NetFox; @?0))@kPc3
RE]*fRe7#
_u~`RlA
import java.io.*; scrss
import java.net.*; *WWDwY@!u
JX{rum
{L M Q
public class FileSplitterFetch extends Thread { /}5)[9GC
%GMCyT
C MGDg}
String sURL; //File URL +)_DaL E
long nStartPos; //File Snippet Start Position :8?l=B9("g
long nEndPos; //File Snippet End Position CXi:?6OG
int nThreadID; //Thread's ID f\Q_]%^W
boolean bDownOver = false; //Downing is over )|Ka'\xr
boolean bStop = false; //Stop identical kn&BGYt
FileAccessI fileAccessI = null; //File Access interface N[yS heT
Qv8 =CnuOT
`vf]C'
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException C2DAsSw
{ Kzwe36O;?
this.sURL = sURL; yv$hIU2X
this.nStartPos = nStart; $5Rx>$~+d
this.nEndPos = nEnd; G^/8^Zi
nThreadID = id; )31xl6@
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C7&L9k~jf
} ;iUO1t)^
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~D/1U)kt
public void run() b~TTz`HZ
{ A[:(#iR5-E
while(nStartPos < nEndPos && !bStop) fvA167\
{ \GGyz{i
W!* P
;9vY5CxzC
try{ #aKUD
URL url = new URL(sURL); JPg^h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); x3nUKQtk:8
httpConnection.setRequestProperty("User-Agent","NetFox"); nKjT&R
String sProperty = "bytes="+nStartPos+"-"; &uf|Le4
httpConnection.setRequestProperty("RANGE",sProperty); x5M+\?I<2
Utility.log(sProperty); g}*p(Tp9:
)k4&S{=
~!/agLwY
InputStream input = httpConnection.getInputStream(); ?H8dyQ5"
//logResponseHead(httpConnection); ]tmMk7
veS) j?4
"R% RI( y{
byte[] b = new byte[1024]; xhMAWFg|
int nRead; NK%Ok
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FbW$H]C$
{ ;i?R+T
nStartPos += fileAccessI.write(b,0,nRead); iD>H{1 h
//if(nThreadID == 1) bj?=\u
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <J.q[fd1*
} (Hs,Tj
V&lx0Dy
6Z@T /"mU(
Utility.log("Thread " + nThreadID + " is over!"); V2'5doo
bDownOver = true; hXD/
//nPos = fileAccessI.write (b,0,nRead); 6E_YUk?KW
} =(v'8?--
catch(Exception e){e.printStackTrace ();} 65rf=*kz:
} Mh@n>+IR
} LeNSjxB
s Dsq:z
7{NH;U t
//打印回应的头信息 C879eeJ
public void logResponseHead(HttpURLConnection con) @r\{iSg&g.
{ q/qig5Ou
for(int i=1;;i++) h)z2#qfc
{ #E_<}o
String header=con.getHeaderFieldKey(i); #+|0o-
if(header!=null) U/h@Q\~U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); STPRC&7;
Utility.log(header+" : "+con.getHeaderField(header)); Lw<.QMN%f
else Y6(=cm
break; NGW:hgf
} bE3mOml
} 9A9T'g)Du
&/g^J\0M)
Ss\FSEN!/
public void splitterStop() F|8;Swb5
{ 8T"kQB.Zv
bStop = true; y-"QY[
} :kd]n$]
8wn{W_5a
t8*NldC
} }?sC1]-j&
EIPXq
6wZ)GLW[
/* =RQI5nHdw
**FileAccess.java $\PU Y8
*//文件访问(定位，写) \(r$f!`
package NetFox; ;{v2s;
import java.io.*; #J
f|~X}R
}eveNPB{5
public class FileAccessI implements Serializable{ >G As&\4hs
9q\_UbF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 CW]Th-xc
RandomAccessFile oSavedFile; @R(Op|9
long nPos; A>_,tt
Y)l=r^Ap>
J :KU~`r
public FileAccessI() throws IOException q)J5tBfJ
{ 1Afy$It/{
this("",0); j}6h}E&dEr
} V~do6[(
tjx|;m7
ZEvK
public FileAccessI(String sName,long nPos) throws IOException )g KC}_h=
{ ?F*I2rt#
oSavedFile = new RandomAccessFile(sName,"rw"); %al 5 {
this.nPos = nPos; S27s Rxfr
oSavedFile.seek(nPos); zU_dk'&,
} %OP|%^2
iU(B#ohW"
@ 'U`a4
public synchronized int write(byte[] b,int nStart,int nLen) 6Xbf3So
{ Q2F20b
int n = -1; Q8$;##hzt
try{ {uJ"%
oSavedFile.write(b,nStart,nLen); SIc~cZ!Yu
n = nLen; _CBMU'V
} "/Gw`^t
catch(IOException e) c:<a"$
{ m7i(0jd +
e.printStackTrace (); }{Ra5-PY
} ):y^g:
V/zmbo)
*p9k> )'J
return n; N7YCg
} B![:fiR`
<qEBF`XP=
:[0)Uu{
} 9~jS_Y)"
1qBE|PwBp
X-J85b_e
/* *kcc]*6@s
**SiteInfoBean.java 6~x a^3G:
*/ tD4-Llj6
package NetFox; eC L_c>3!
$RUK<JN$6
u! dx+vd
public class SiteInfoBean { ^Y5I OX:
#rNc+
UT[{NltH
private String sSiteURL; //Site's URL $xcZ{C
private String sFilePath; //Saved File's Path {L [
private String sFileName; //Saved File's Name hMUUnr"8;i
private int nSplitter; //Count of Splited Downloading File -= izu]Fb,
$1Zr.ERL|(
S(CVkCP
public SiteInfoBean() 'fCSP|
{//nSplitter的缺省值为5 LXPO@2QF
//default value of nSplitter is 5 2A9crL$
this("","","",5); C%CgWO`Xj
} %5nEyZOq
%~,Fe7#p
R.vOYzo
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yO,Jgn
{ 1}+b4"7]
sSiteURL= sURL; n$9Xj@+
sFilePath = sPath; E&5S[n9{3
sFileName = sName; owb+,Gk(
this.nSplitter = nSpiltter; ^7Z;=]8J
S4-jFD)U
t)rPXvx}!
} 0WYu5|
'2|P-/jU
Mc!LC .8
public String getSSiteURL() (U_HX2f
{ bOp%
return sSiteURL; D5f[:
} (hg6<`
8Op^6rX4
jzBW'8
public void setSSiteURL(String value) 0,Ib74N'w
{ .yFO] r1aL
sSiteURL = value; KWAd~8,mk
} oe0YxSauL
Q]3]Z/i
=1'WZp}D5
public String getSFilePath() bf{_U%`
{ 9)o@d`*
return sFilePath; (:?bQA'Td
} )=MK&72r
?~E"!
*ZFF$0}
public void setSFilePath(String value) J9DI(`
{ {9.UeVz
sFilePath = value; 3IB9-wG
} *X ;ch55\
8eYEi
=tP^vgfQ
public String getSFileName() + #E?)
{ 7J ?s&x
return sFileName; B([-GpZt[
} 'J5F+,\Ka
K2e*AE*
^u1Nbo
public void setSFileName(String value) 8#- Nx]VM
{ uXLZ!LJo
sFileName = value; %e3E}m>
} V0W4M%
V\opC6*L_e
DS>&|zF5l
public int getNSplitter() :Ea|FAeK8
{ ;Bj&9DZd
return nSplitter; z!18Jh
} `h'=F(v(}
,S(s
8oXp8CC
public void setNSplitter(int nCount) q9{)nU
{ 1s(]@gt
nSplitter = nCount; m<kJH<!j
} yNn=r;FZQ
} v+`'%E
)pT5"{
"#-iD
/* aR('u:@jHi
**Utility.java Il(o[Q>jJ3
*/ 96QY0
package NetFox; CSq|R-@<U
c00rq ~<K
vCSC:
public class Utility { 5U4V_*V
9y;}B y
\AA9 m'BZ
public Utility() NH}o`x/
{ _>kc:
g,M-[o=Fk
d;wq@e
} "`cPV){]
b=pk;'-
//线程睡眠 J:>o\%sF
public static void sleep(int nSecond) zwJ&K;"y(
{ J'7;+.s(
try{ GEh(pJ
Thread.sleep(nSecond); vM5/KrW
} e@TwZ6l
catch(Exception e) %6 GM[1__
{ *AGf'+j*z
e.printStackTrace (); ?eX/vqk
} yt="kZ
} W} H~ka
Y)1J8kq_
//日志 qGEp 6b H
public static void log(String sMsg) a%si:_
{ ty rP[y
System.err.println(sMsg); (l-=/6-
} Zl3e=sg=
~yw]<{?
~LV]cX2J(
public static void log(int sMsg) >dm9YfQ
{ Q1x&Zm1v
System.err.println(sMsg); Lw_|o[I}
} <bSPKTKL
} J`GL_@$q
$,U/,XA {E
?Z?(ky!
/* x4L3Z__
**TestMethod.java q{f\_2[
*/ RJerx:]
package NetFox; PQSmBTs.
KA?%1s(kJ
sCrP+K0D
public class TestMethod { ,zHL8SiTX
tcv(<0
V,d\Wkk/
public TestMethod() O_4B> )zd
{ ///xx/weblogic60b2_win.exe jaKW[@<
try{ x< 2]UB`
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); R<6y7?]bZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Qg(;>ops
SiteFileFetch fileFetch = new SiteFileFetch(bean); ; YQB
fileFetch.start(); g@4~,
} :?g+\:`/0j
catch(Exception e){e.printStackTrace ();} ,@?9H ~\
rXD:^wUSc
Fb%?qaLmCv
} K|-m6!C!7
GPhhg
l7^^MnkC
public static void main(String[] args) B;e<.M)e
{ Q8m%mJz~]
new TestMethod(); j8[U}~*^
} MkJBKS
} qAH^BrJ
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