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)); VgZaDd;
} Uh|__DUkh
for(int i=0;i<nEndPos.length-1;i++) )`+@j.75
{ )D@n?qbG
nEndPos = nStartPos[i+1]; ,<P[CUD&&
} *A1TDc$
nEndPos[nEndPos.length-1] = nFileLength; }jY[| >z
} cVHE}0Xd(
} R$;&O. 5M
YT(1 "{:
xm10
//启动子线程 % 6hw
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,8"[ /@
for(int i=0;i<nStartPos.length;i++) C}P \kDM
{ ?'/5%f`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), T;[c<gc/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), , w'$T)
nStartPos,nEndPos,i); 97))'gC
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ?.Yw%{?TG
fileSplitterFetch.start(); ;`PkmAg
} PSQ:'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `)C`_g3Ew
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CpqSn/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", v yLAs;
nEndPos = " + nFileLength); v.2Vg
// fileSplitterFetch[nPos.length-1].start(); F/od,w9_
~q T1<k
yDyeP{
//等待子线程结束 }B '*8^S
//int count = 0; Qhr]eu;z
//是否结束while循环 ?^$4)Y>Kf
boolean breakWhile = false; ^.1VhTB
BfE-s<
-J7,Nw
while(!bStop) c'#J{3d
{ 6[|<
write_nPos(); ,f0g|5yDf
Utility.sleep(500); AB&wn>q
breakWhile = true; ;{q) |GRF
?! _pP|
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for(int i=0;i<nStartPos.length;i++) :0j`yo:w
{ //5_E7Ehu$
if(!fileSplitterFetch.bDownOver) w$;*~Qc
{ Ufe
breakWhile = false; :9 iOuu
break; +ZA\M:^b
} 6BN(^y#-X
} kbT-Oz 2
if(breakWhile) Cz);mOb%M%
break; 07"Oj9NlA
W]}V<S$
yqb<<4I
//count++; $~@096`QL<
//if(count>4) Qp{-!*
// siteStop(); s&`XK$p
} r\ Yur
|21hY
VrE5^\k<a
System.err.println("文件下载结束！"); bl>b/u7/6
} |j}F$*SE[
catch(Exception e){e.printStackTrace ();} h5JwB<8
} 0\ w[_H
yIf}b
$(L7/M
//获得文件长度 "3oU (RA
public long getFileSize() Ib8{+j
{ 3 DHA^9<q
int nFileLength = -1; `h3}"js
try{ "EhO )lR
URL url = new URL(siteInfoBean.getSSiteURL()); Jv.R?1;8i
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .);:K
httpConnection.setRequestProperty("User-Agent","NetFox"); KL"L65g&
eniR}
*9(1:N;#
int responseCode=httpConnection.getResponseCode(); Vot+gCZ
if(responseCode>=400) `80Hxp@
{ y+afUJT
processErrorCode(responseCode); "]V|bz o0a
return -2; //-2 represent access is error slfVQ809
} 7O^ S.(
ucPMT0k
k\%v;3nBK
String sHeader; .LR>&N_U
" z'!il#
>!.9g
for(int i=1;;i++) %\&dFwb
{ S5a<L_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); qDd/wR,44
//Utility.log(in.readLine()); #e>MNc 'z
sHeader=httpConnection.getHeaderFieldKey(i); dKpa5f7
if(sHeader!=null) P$Ru NF
{ a\_,_psK
if(sHeader.equals("Content-Length")) |raQ]b@t&
{ beZ| i 1:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n`Iy7X
break; >v,j;[(
} (r\h dLX
} T["(YFCByg
else 7!nAWlQ&-E
break; Hvo27THLo
} XO~^*[K
} ++"PPbOe&D
catch(IOException e){e.printStackTrace ();} H H3
catch(Exception e){e.printStackTrace ();} >{Z=cv/6o
+qf{ '|H
hO@3-SRa,k
Utility.log(nFileLength); y<d#sv(s
Asu"#sd
J3+8s[oJ>
return nFileLength; P<x
} ~"Ki2'j)^]
uwA3!5
L(8dK
//保存下载信息（文件指针位置） uI&M|u:nT
private void write_nPos() rapca'&#
{ Uk\U*\.
try{ @{lnfOESl
output = new DataOutputStream(new FileOutputStream(tmpFile)); _/ZY&5N
output.writeInt(nStartPos.length); N&`ay{&`:
for(int i=0;i<nStartPos.length;i++) UOOme)\>
{ r^^C9"
// output.writeLong(nPos); 1Di&vpn0u
output.writeLong(fileSplitterFetch.nStartPos); uK5x[m
output.writeLong(fileSplitterFetch.nEndPos); |?A-?-
} F|Q#KwN
output.close(); e|yuPd
} I0RWdOK8K
catch(IOException e){e.printStackTrace ();} [Cp{i<C
catch(Exception e){e.printStackTrace ();} y8z%s/gRh
} &[5az/Hj*
L{p-'V
5-^twXC&
//读取保存的下载信息（文件指针位置） +KNr1rG
private void read_nPos() c @fc7
{ j]&{ @Y
try{ C,hsr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); vrbh+
int nCount = input.readInt(); ;D:T ^4
nStartPos = new long[nCount]; }*.*{I
nEndPos = new long[nCount]; 1PSb72h<
for(int i=0;i<nStartPos.length;i++) >.\E'e5^C
{ PM7/fv*,
nStartPos = input.readLong(); q|J]
nEndPos = input.readLong(); \/v$$1p2
} --kK<9J7
input.close(); sKO ;p
} )zo ;r!eP
catch(IOException e){e.printStackTrace ();} I#U44+c
catch(Exception e){e.printStackTrace ();} j83 V$ Le
} Q>$L;1E*,
]EQ/*ct
9l]IE,u
private void processErrorCode(int nErrorCode) *cIXae^Y7
{ ^dv>n]?
System.err.println("Error Code : " + nErrorCode); 7<D_ h/WV
} y{JkY\g
F}>`3//u
BYU.ptiJJ
//停止文件下载 ]U%Tm>s.
public void siteStop() G2D<LRWt4
{ $ cSZX#\
bStop = true; n4johV.#
for(int i=0;i<nStartPos.length;i++) ?f..N,s
fileSplitterFetch.splitterStop(); Kq$1lPI
\.] U
HrGX-6`
} J?'!8,RX
} X)m2{@v D
//负责部分文件的抓取 \ua.%|
**FileSplitterFetch.java g\'sGt3O
*/ ny=iAZM>q
package NetFox; F1>,^qyG6
9lv2
x}d\%*B
import java.io.*; o@. !Z8
import java.net.*; s8Oz^5p(
e-mlvi^-
fp0Va!T(V
public class FileSplitterFetch extends Thread { ZV;yXLx|
qv6]YPP
|:z%7J3wP
String sURL; //File URL Yo:&\a K[
long nStartPos; //File Snippet Start Position l<0V0R(
long nEndPos; //File Snippet End Position > R=YF*t
int nThreadID; //Thread's ID zdCt#=QV?R
boolean bDownOver = false; //Downing is over Za w+
boolean bStop = false; //Stop identical JK4 @
FileAccessI fileAccessI = null; //File Access interface CR<l"~X
2dfA}i>k
GcuZPIN%D
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >nX'RE|F
{ .+yJ'*i$d
this.sURL = sURL; <FEO6YP
this.nStartPos = nStart; bX,Z<BvbF
this.nEndPos = nEnd; EX_&wep@1
nThreadID = id; M3%<kk-_
fileAccessI = new FileAccessI(sName,nStartPos);//定位 'mF}+v^
} =#fqFL,
yrw!b\
fJuJ#MX{:
public void run() JFfx9%Fq
{ R<-KXT9
while(nStartPos < nEndPos && !bStop) &3<]FK
{ +Q.[W`goV
M:x(_Lu
+dfSCs
try{ sC>8[Jatd
URL url = new URL(sURL); i+}M#Y-O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ("Zi,3"+
httpConnection.setRequestProperty("User-Agent","NetFox"); bGZy0.
String sProperty = "bytes="+nStartPos+"-"; L6T_&AiL$
httpConnection.setRequestProperty("RANGE",sProperty); aC*J=_9o#
Utility.log(sProperty); n" sGI
`|R{^Sk1o
K\G|q}E/1
InputStream input = httpConnection.getInputStream(); TUG3#PSnm*
//logResponseHead(httpConnection); Mtu8zm
xQQ6D
0!Yi.'+
byte[] b = new byte[1024]; 6o!"$IH4
int nRead; ^IpS 3y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ne%X:h
{ WVZ\4y
nStartPos += fileAccessI.write(b,0,nRead); n):VuOjm
//if(nThreadID == 1) AOpfByw
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fOfp.`n
} YpJzRm{Ra
Hogr#Sn2
<javZJ
Utility.log("Thread " + nThreadID + " is over!"); Y3?kj@T`i
bDownOver = true; uJQeZEe
//nPos = fileAccessI.write (b,0,nRead); HO"(eDW6z
} >|<6s],v
catch(Exception e){e.printStackTrace ();} J{H475GqiT
} }U9e#>ex
} a`}-^;}SW
!T}`h'
C4y<+G.`
//打印回应的头信息 pxgv(:Tw
public void logResponseHead(HttpURLConnection con) ;k>{I8L~
{ FXbNmBXF
for(int i=1;;i++) AWw:N6\
{ &f[[@EF7
String header=con.getHeaderFieldKey(i); ipsNiFv:
if(header!=null) /)~McP3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [X|P(&\hQd
Utility.log(header+" : "+con.getHeaderField(header)); OA+W$
else d/e9LK
break; 7{6wNc
} fy-(B;
} epQ7@9,Q
yt?#T#
X]N8'Yt
public void splitterStop() h<?Vzl
{ kHJjdgV
bStop = true; GE>&fG
} uy$o%NL-7
_$r+*nGDz
d<y B ~Y
} fSj^/>
$lvpBs
~`y6YIJ3
/* B|!Re4`0
**FileAccess.java d6uL;eR
*//文件访问(定位，写) )pg?ZM9
package NetFox; lm$T`:c
import java.io.*; wDn5|F}i&
U@H SU%H
W)KV"A3C
public class FileAccessI implements Serializable{ x,n;GR
8ED6C"6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 wuPx6hCl
RandomAccessFile oSavedFile; &TKB8vx=#
long nPos; @hk~8y]rz
905 /4z'
;#AV~Y- s
public FileAccessI() throws IOException j &~OR6
{ (i {
this("",0); xR$xAcoSB
} 1Eh(U
*\emRI>
$///N+B
public FileAccessI(String sName,long nPos) throws IOException C/)Xd^#
{ 5K,Y6I&$SJ
oSavedFile = new RandomAccessFile(sName,"rw"); W}Z'zU?[
this.nPos = nPos; 0Nmd*r
oSavedFile.seek(nPos); K?) &8S
} @X|CubJ
E;k'bz
9%|!+!j
public synchronized int write(byte[] b,int nStart,int nLen) (R{WJjj
{ )nQ.6
int n = -1; cO' \s
try{ fxjs"rD5
oSavedFile.write(b,nStart,nLen); }.x?$C+\"
n = nLen; a(F%M
} A%pcPzG;
catch(IOException e) {@k5e) Q
{ K"eW.$
e.printStackTrace (); QD<f)JZK
} /mmCqP
|[8&5[);
"Q^Ck7
return n; '(;`t1V8k
} rlgp1>89
S_WYU&8
Mc9%s$MT
} c{zQX0
MC^H N w
q'[5h>Pa
/* 4&}LYSZl
**SiteInfoBean.java 2}K7(y!?u
*/ 0X.pI1jCO
package NetFox; Yz4Q!tL
S-*4HV_l
tAefBFu
public class SiteInfoBean { SZNM$X|T
Eb[*nWF=
Tmqtj
private String sSiteURL; //Site's URL :A>cf}
private String sFilePath; //Saved File's Path BZe x
private String sFileName; //Saved File's Name h49|x&03
private int nSplitter; //Count of Splited Downloading File 3 cu`U`
M#UW#+*g!
lo Oh }y+
public SiteInfoBean() J;HkR9<C
{//nSplitter的缺省值为5 eVS6#R]'m
//default value of nSplitter is 5 5?{a=r9
this("","","",5); 2/3,%5j_
} uL`;KD
b|P[\9
\}Z5}~S
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) xx_]e4
{ pO[ @2tF
sSiteURL= sURL; x[zt(kC0+
sFilePath = sPath; D:4Iex9$F"
sFileName = sName; (w}iEm\b
this.nSplitter = nSpiltter; h,"K+$
LY(YgqL
W{<_gD9
} r>+\9q1
r3*0`Rup
-A^18r
public String getSSiteURL() VyK[*kyN
{ j#rjYiYKy
return sSiteURL; /I(IT=kp
} Yj;KKgk
~dg7c{o5
],V_"\ATD
public void setSSiteURL(String value) OrNi<TY>
{ ~bC{R&p
sSiteURL = value; @m[q0G}
} kaqH.e(
jvv3;lWDL.
`7[z%cuK
public String getSFilePath() yY+)IU.
{ |uf{:U)
return sFilePath; xM"k qRZ
} pUi|&F K">
m^I+>Bp/:
F%M4i`Vh
public void setSFilePath(String value) `f?v_Ui-$
{ 0]p! Bscaf
sFilePath = value; 46OYOa
} I?r7dQEm
r)E9]"TAB
e=e^;K4
public String getSFileName() O/ Yz6VQ
{ ^E{M[;sF3y
return sFileName; bk^W]<:z`
} LX;w~fRr.
QhR.8iS
I6@98w}"
public void setSFileName(String value) ;;;aM:6\
{ >zx]% W
sFileName = value; <+o*"z\mI
} 1$mxMXNsJ
'Km ~3t
2^RWGCEv
public int getNSplitter() ;r'y/Y'?
{ E0?R,+>&4
return nSplitter; 6:_@;/03%
} IdTatE|^
qmQ}
vMG>Xb
public void setNSplitter(int nCount) -hL0}Wy$N
{ [&y="6No
nSplitter = nCount; s[<a(
} a_}k^zw(
} =)QtE|p,77
{<$ D|<S
%8C,9q
/* d^b(Uo=$
**Utility.java z 3((L
*/ TNun)0p
package NetFox; +pMa-{
Zfwhg4G~
vfBIQfH
public class Utility { v_=xN^R
k_d)
f0"N
public Utility() LelCjC{`1
{ b~$B0o)
=T7lv%u
Qg9*mlm`
} 3%HF"$Gg
n@1;5)&k~
//线程睡眠 q-? k=RX`
public static void sleep(int nSecond) PH!^ww6
{ 4sJM!9eb[
try{ -o: ifF|
Thread.sleep(nSecond); 'OEh'\d+x
} itotn!Wb`
catch(Exception e) 3jR>
{ JdYmUM|K/c
e.printStackTrace (); B8=r^!jEL
} n{Ce%gy
} uO]^vP]fT
4S9hz
//日志 8&K1;l }
public static void log(String sMsg) Ebk9[=
{ TTGk"2 Q'
System.err.println(sMsg); "Sx}7?8AB
} WC0gJy
q!fdiv`
+,8j]<wpo
public static void log(int sMsg) b\ P6,s'(
{ FR57F(31
System.err.println(sMsg); @$:T]N3m
} Nj5V" c
} X6h@K</c^:
+O]jklS4H
WRdBL5
/* $~^Y4 } m
**TestMethod.java <t~RGn3
*/ k 'CM^,F&
package NetFox; O\~/J/u <
^k#.;Q#4
}^b7x;O|
public class TestMethod { h eR$j
ng0tNifZ;
pYxdE|2j
public TestMethod() 76'@}wNnw
{ ///xx/weblogic60b2_win.exe V?[dg^*0
try{ aB$xQ|~
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); EdH;P\c
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xY_<D+OV
SiteFileFetch fileFetch = new SiteFileFetch(bean); $4Vpl
fileFetch.start(); [<0\v<{`L
} \N|ma P
catch(Exception e){e.printStackTrace ();} #.j[iN :+
JXhHitUD
(7zdbJX
} K-<kp!v
^Fop/\E
?^X e^1(
public static void main(String[] args) ^i;y2c
{ ezz;NH
new TestMethod(); jIvSjlmI
} O,D/&0
} \c1NIuJR
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