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)); uPl}NEwU|
} $3 -QM
for(int i=0;i<nEndPos.length-1;i++) (@XQ]S}L
{ OgIRI8L
nEndPos = nStartPos[i+1]; N Nk
} |8CxMs
nEndPos[nEndPos.length-1] = nFileLength; W..*!UGl
} Pz0MafF|T
} s,#We} bv
Vq]ixag2^
v%cCJ SO#
//启动子线程 G$TO'Ciu:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; |3e+ K.
for(int i=0;i<nStartPos.length;i++) D(']k?
{ ,3_Sf?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |D-[M_T5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), E&kv4,
nStartPos,nEndPos,i); SgxrU&::
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Pp!4Ak4TT9
fileSplitterFetch.start(); YdO*5Gb6
} $?W2'Xm!V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xAd@.^
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;G8H'gM07
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1xS+r)_n@
nEndPos = " + nFileLength); 2mzn{S)nV
// fileSplitterFetch[nPos.length-1].start(); j8Z;}Ps
7d%x7!E
tIDN~[1
//等待子线程结束 1!(lpp
//int count = 0; YOLzCnI4
//是否结束while循环 -)(=~|,Pq/
boolean breakWhile = false; 1-E6ACq
\ZADY.ha
iS+"Jsz
while(!bStop) I{dy,\p
{ b)'CP Cu*
write_nPos(); RKzty=j4
Utility.sleep(500); #<[&Lw
breakWhile = true; 1Zc=QJw@
d*{Cv2A.
%r1#G.2YW
for(int i=0;i<nStartPos.length;i++) W !j-/ql
{ n-8/CBEH(
if(!fileSplitterFetch.bDownOver) Ll; v[Y
{ 9#U]?^DJ@
breakWhile = false; 0yC~"u[N Y
break; VB*c1i
} ;=0mL,
} 6k;5T
if(breakWhile) <$-^^b(y
break; ^ 34Ng
+'gO%^{l
5@>hjXi"Y
//count++; 2fr%_GNu
//if(count>4) *d=}HO/
// siteStop(); SeXgBbGAne
} vVo'f|fW
2o<*rH
u=InE|SH
System.err.println("文件下载结束！"); %HpPTjAW
} Cydo~/
catch(Exception e){e.printStackTrace ();} GYQ:G=
} {2:baoG-
z{OL+-OY
eGQ4aQhi
//获得文件长度 3G4WKg.^
public long getFileSize() KdozB!\
{ heIys.p
int nFileLength = -1; el5Pe{j'
try{ V.`hk^V,
URL url = new URL(siteInfoBean.getSSiteURL()); J&\Q3_vro9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3HtM<su*h
httpConnection.setRequestProperty("User-Agent","NetFox"); ^}$t(t
>4wigc
i/_rz.c~3
int responseCode=httpConnection.getResponseCode(); f91]0B`C
if(responseCode>=400) >mA]2gV<a
{ Y<W9LF
processErrorCode(responseCode); iSf%N>y'K
return -2; //-2 represent access is error 16Ka>=G
} geK;r0(f
hJ8&OCR }
%_:L_VD@
String sHeader; 19GF%+L ,
r&R~a9+)
)R `d x
for(int i=1;;i++) 83vZRQw
{ >b\|%=(x!*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); v0) %S
//Utility.log(in.readLine()); 0);5cbV7i
sHeader=httpConnection.getHeaderFieldKey(i); -<x%
if(sHeader!=null) o0No"8DnjH
{ ?yAb=zI1b
if(sHeader.equals("Content-Length")) 90+Vw`Gz=
{ .&b^6$dC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M/W9"N[ta
break; 1d49&-N
} ]vcT2lr]
} M)K!!Jqh
else ("=q-6$G
break; Oi|cTZ@A-
} E^n!h06~G
} [MAPa
catch(IOException e){e.printStackTrace ();} n+=7u[AZi
catch(Exception e){e.printStackTrace ();} 0aR.ct%
bhRa?wuoY
5D/Td#T04
Utility.log(nFileLength); OF1^_s;
81#x/&E]
a++gwl
return nFileLength; p Cx_[#DrP
} #QlxEs#%
qYe`</
@+~URIG)
//保存下载信息（文件指针位置） &0*l:uw
private void write_nPos() ![{/V,V]~
{ 2vUcSKG7
try{ >9nVR
output = new DataOutputStream(new FileOutputStream(tmpFile)); '#A_KHD
output.writeInt(nStartPos.length); ]Y?ZUSCJ
for(int i=0;i<nStartPos.length;i++) se3EI1e
{ C-49u<;,
// output.writeLong(nPos); g;R
output.writeLong(fileSplitterFetch.nStartPos); E}w5.1
output.writeLong(fileSplitterFetch.nEndPos); 1l}Am>}
} 8$JJI({bH
output.close(); v^/<2/E"?4
} Z 5 .cfI[
catch(IOException e){e.printStackTrace ();} - ]We|{
catch(Exception e){e.printStackTrace ();} NmpNme
} FLsJ<C~/~
Vd.XZ*}r*
RigS1A\2l
//读取保存的下载信息（文件指针位置） [4;_8-[Nv
private void read_nPos() es69P)
{ OI/]Y7D[Oq
try{ *mn9CVZ(}M
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Kzt:rhiB
int nCount = input.readInt(); bjj F{T
nStartPos = new long[nCount]; pR*3Q@Ng
nEndPos = new long[nCount]; 3M^`6W[;
for(int i=0;i<nStartPos.length;i++) mT j
{ TgRG6?#^l
nStartPos = input.readLong(); 2,|@a\H
nEndPos = input.readLong(); dj,lbUL
} K;`*n7=IA
input.close(); Cx) N;x
} 9)b{U2&
catch(IOException e){e.printStackTrace ();} e \kR/<L
catch(Exception e){e.printStackTrace ();} E/% F0\B
} E}36
'r^'wv]
M-!#-l
private void processErrorCode(int nErrorCode) H0Sm4
{ #s}tH$MT#
System.err.println("Error Code : " + nErrorCode); z;0]T=g
} hg+;!|ha
1mEW]z
ri9n.-xs
//停止文件下载 el^<M,7!
public void siteStop() Z\?!&&
{ a ?wg~|g
bStop = true; w6B`_Z'f
for(int i=0;i<nStartPos.length;i++) pAEJ=Te
fileSplitterFetch.splitterStop(); +@rc(eOwvN
@zix%x
H/G;hk
} xJvalb
} i079 V
//负责部分文件的抓取 52 DSKL
**FileSplitterFetch.java 8HSGOs =8
*/ Ga*
package NetFox; k"FY &;G(G
j!"NEh78H
1[dQVJqMp(
import java.io.*; wi:d!,P`e
import java.net.*; ;Y &2G'
'Cywn^Ym#
`,wX&@sN
public class FileSplitterFetch extends Thread { E~Y%x/oX
6Qm .k$[
lzZ=!dG
String sURL; //File URL *\wf(o>Q
long nStartPos; //File Snippet Start Position X`daaG_l
long nEndPos; //File Snippet End Position ;77q~_g$
int nThreadID; //Thread's ID odq3@ ziO
boolean bDownOver = false; //Downing is over _ID =]NJ_
boolean bStop = false; //Stop identical [WunA,IuR
FileAccessI fileAccessI = null; //File Access interface iwEHEi%
z:W1(/W~
Yf^/YLLS
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i0&]Ig|;
{ e-o$bf%
this.sURL = sURL; P,Rqv)}X
this.nStartPos = nStart; ["?WVXCF8|
this.nEndPos = nEnd; rxIYgh
nThreadID = id; AqP\g k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 1^=[k
} g.O? 1bebe
0 :1ldU 4
Z{.L_]$I
public void run() "LH*T
{ 6NqLo^ "g
while(nStartPos < nEndPos && !bStop) ,k3aeM~`%w
{ o!t1EPJE*
^-7{{/
i0~L[v9l<
try{ d "vd_}P~
URL url = new URL(sURL); `<l|XPv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j2|!h%{nI
httpConnection.setRequestProperty("User-Agent","NetFox"); O/R>&8R$
String sProperty = "bytes="+nStartPos+"-"; |k9A*7I
httpConnection.setRequestProperty("RANGE",sProperty); =!Y{Mz
Utility.log(sProperty); 7dU7cc
DK;/eZe
MtO p][i
InputStream input = httpConnection.getInputStream(); cB[.ET$
//logResponseHead(httpConnection); YPq`su7m9
pBu~($%d
w]0jq U6
byte[] b = new byte[1024]; *8CE0;p'k
int nRead; W(tXq
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RsDI7v
{ a?!Joi[
nStartPos += fileAccessI.write(b,0,nRead); KPA5 X]
//if(nThreadID == 1) oYN# T=Xi
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w8g36v*+(u
} 1P\_3.V{
MPd#C*c
Kn9,N@bU_
Utility.log("Thread " + nThreadID + " is over!"); MY[" zv
bDownOver = true; AH],>i3
//nPos = fileAccessI.write (b,0,nRead); ~qT+sc!t
} }a_: oR
catch(Exception e){e.printStackTrace ();} b\\?aR |
} .ODtduURe
} 0\U28zbMJw
c~|/,FZU'
g `B?bBg
//打印回应的头信息 #UJ@P Dwil
public void logResponseHead(HttpURLConnection con) u;:N 4d=f'
{ {ersXQ:
for(int i=1;;i++) +T^m
{ rd1&?X
String header=con.getHeaderFieldKey(i); O'-lBf+<
if(header!=null) [*>@hx
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Rb~Kyy$
Utility.log(header+" : "+con.getHeaderField(header)); *qBMt[a
else 1^Zx-p3J
break; Krq^|DY
} "5jZS6A]
} ._tv$Gd@k
I"JT3[*s
d*>M<6b-
public void splitterStop() |#2<4sd
{ XLbrE|0A?
bStop = true; `?6m0|\@
} uX0wg
0 q3<RX>M%
Cm;N5i
} U0N[~yW(t1
#t(?8!F
"msg./iC
/* [bOy,^@4
**FileAccess.java {h%.i Et%
*//文件访问(定位，写) tc,7yo\".
package NetFox; 329xo03-[
import java.io.*; )sS<%Xf
"?9fL#8f*!
&gEu%s^wR
public class FileAccessI implements Serializable{ wA~Nfn ^
_RmE+Xg2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tt[_+e\4
RandomAccessFile oSavedFile; wFd*6%
long nPos; F9+d7 Y$
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p$%h!.~99T
public FileAccessI() throws IOException G#*!)#M <
{ OVh/t#On
this("",0); 8DI|+`OgW
} ' R@<4Ib|
yED^/=\)}
oF6MV&q/
public FileAccessI(String sName,long nPos) throws IOException :<v$vER,&
{ k?8W2fC
oSavedFile = new RandomAccessFile(sName,"rw"); Cg|uHI*
this.nPos = nPos; %5KR}NXX6
oSavedFile.seek(nPos); 'OihA^e
} Vlz T
zg j35
-$kJERvy
public synchronized int write(byte[] b,int nStart,int nLen) ?7p| F^
{ 1!C,pXU#:
int n = -1; @}Z/{Z[@
try{ 1c4%g-]7
oSavedFile.write(b,nStart,nLen); Rj&7|z
n = nLen; JS:lysu
} !?>)[@2 k6
catch(IOException e) 9]w0zUOL6
{ UKBMGzu2:
e.printStackTrace (); mpivg
} .0-m=3mp2
yk)j;i4@
`;qZ$HH
return n; 3# (5Kco
} c>!J@[,
Ny'v/+nQ
eC{Z
} ^k(eRs;K
@[RY8~
4~Pto f@
/* ~b[4'm@
**SiteInfoBean.java -8jqC6mQ
*/ h3IkOh4|h
package NetFox; gWo~o]f
L _y|l5
15:@pq\
public class SiteInfoBean { @/(7kh+
6)$N[FNs
PZR%8 m}]u
private String sSiteURL; //Site's URL ')-(N um
private String sFilePath; //Saved File's Path G0>Wk#or
private String sFileName; //Saved File's Name =*}Mymhk(
private int nSplitter; //Count of Splited Downloading File ^z;,deoGh
e:D"_B
* _lo;
public SiteInfoBean() ejY5n2V#=
{//nSplitter的缺省值为5 B[B<U~I}
//default value of nSplitter is 5 :t S"sM
this("","","",5); %d J>8.jW@
} Kn$1W=B1.
7 aD&\?
3F}KrG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U(=9&c@]
{ *m@w^In^
sSiteURL= sURL; /j/%wT2m
sFilePath = sPath; <^_Vl8%
sFileName = sName; %=8(B.I!
this.nSplitter = nSpiltter; f}Tr$r
z\8yB`8b^
F'$S!K58
} cu`J2vm3
`A _8nW)
Zt2@?w;
public String getSSiteURL() \u-e\w
{ +Cg"2~
return sSiteURL; N$&ePU J
} 3e6Y
:U.)YHY
qZsddll
public void setSSiteURL(String value) &:I +]G/W
{ tm1UH 4
sSiteURL = value; `s>=Sn&UP
} ,Zf!KQw
r82o[+$u0K
IPR tm!
public String getSFilePath() T|s0qQi
{ ;;'a--'"
return sFilePath; fTHun?Vn
} [&qbc#L
/Ej]X`F
nlebFDb7
public void setSFilePath(String value) 42>m,fb2[
{ 51M^yG&M
sFilePath = value; l \^nC2
} r%,H*DOu
ff}a <w
ZutB_uW
public String getSFileName() Lcs{OW,
{ 2>}\XKF).
return sFileName; d$_q=ywc
} #jLaIXms
WTD49_px
OOBcJC
public void setSFileName(String value) O GFE*
{ !-5S8b
sFileName = value; W8,tl>(
} crNjI`%tw
.^LL9{?
uPFHlT
public int getNSplitter() 9vp%6[
{ D!RE-w92X
return nSplitter; ]`@]<6
} \POnsM)+l
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'8l yj&
public void setNSplitter(int nCount) !b7'>b'J<1
{ 3@yTzaq6
nSplitter = nCount; :6W^ S/pf
} JEsLF{
} `.>k)=F&
X7H'Uk9:
*^D@l%av;
/* fK'.wX9
**Utility.java B [+(r
*/ Ns2,hQFc
package NetFox; /^'Bgnez
RVkU+7
l`b1%0y
public class Utility { JY2/YDJ
hV-VeKjZ(
I7fb}j`/
public Utility() _~;&)cn,0
{ I/On3"U%
eyT>wma0
1yBt/U2
} 9c6czirwR^
C,A!tj7@
//线程睡眠 Q(510)
public static void sleep(int nSecond) V#0 dGP-Z
{ &~~aAg
try{ 22`oFXb'
Thread.sleep(nSecond); V1SqX:;b&
} {~bIA!kAFI
catch(Exception e) uf)W-Er6~
{ +Edzjf~Tt
e.printStackTrace (); p$Kj<:qiP
} sM9FE{,mx
} <S1??
keLR1qf
//日志 *Jvxs R'a1
public static void log(String sMsg) $Y6I_U
{ J I<3\=:+
System.err.println(sMsg); v6s\Z\v)Q`
} 'K@-Z]
D ]OD.
:{LAVMG&^
public static void log(int sMsg) fb\DiKsW
{ P+<BOG|m
System.err.println(sMsg); ]3*P:$Rq
} 8|O=/m^]
} ^=EjadVQ
M`GP^Ta
RMoJz6^>
/* 25:Z;J>
**TestMethod.java zZ%DtxUoU.
*/ GCT@o!
package NetFox; Q1Ux!$_
6*IpAIh
57~Uqt
public class TestMethod { WwuZ(>|
Sw)i1S9
WsR+Np@c
public TestMethod() G.g|jP'n
{ ///xx/weblogic60b2_win.exe W>B^S
try{ g\U/&.}DN
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hd B |#t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j{"z4Y4
SiteFileFetch fileFetch = new SiteFileFetch(bean); "O*x' XhN
fileFetch.start(); z}ElpT[(;
} ak;6z]f8[
catch(Exception e){e.printStackTrace ();} X7aYpt;
B0d%c&N${
c'Z:9?#5
} jin db#)bz
fc@'9-pt
ebC)H
public static void main(String[] args) +4et7
{ 2j&v;dmh<
new TestMethod(); !\-WEQrp\
} P7:d ly[,q
} }aF
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