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)); ]lz,?izMR
} >:OOuf#
for(int i=0;i<nEndPos.length-1;i++) qf)]!wU9
{ 9!bD|-6y
nEndPos = nStartPos[i+1]; ((.PPOdJV
} gl]{mUZz}
nEndPos[nEndPos.length-1] = nFileLength; c0Q`S"o+
} . s? ''/(
} gP/]05$e
IFG`
*ZN"+wf\
//启动子线程 E_ mgYW*5
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; CXUNdB
for(int i=0;i<nStartPos.length;i++) *ArzXhs[
{ jy&p_v1
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fi7pq2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), _$cQAH0 E
nStartPos,nEndPos,i); #7Qn\C2
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ]t(g7lc}U
fileSplitterFetch.start(); 4RTEXoXs
} YnJ=&21
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F<'g6f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )x( *T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9oc[}k-M
nEndPos = " + nFileLength); 'J!P:.=a>
// fileSplitterFetch[nPos.length-1].start(); jS R:ltd
*:YW@Gbm
SvI
//等待子线程结束 /x$jd)C
//int count = 0; <6(u%t0k5
//是否结束while循环 r\Man'h$
boolean breakWhile = false; WqYl=%x"{V
%eD&2$q*
4jG@ #
while(!bStop) z2"2Xqy<U
{ R?l>Vr
write_nPos(); $Q47>/CUc^
Utility.sleep(500); *l7 ojv
breakWhile = true; Bljh'Qp>C
E(u[?
q/4PX
for(int i=0;i<nStartPos.length;i++) ^~(bm$4r
{ =FwFqjvl
if(!fileSplitterFetch.bDownOver) c!kbHZ<Z
{ i~K~Czmok+
breakWhile = false; 4{fi=BA
break; #lJF$
} =q6yb@
} |W#^L`!G
if(breakWhile) Bb-x1{t
break; ,{E'k+
Xc Pn
pdtK3Pf
//count++; +d#ZSNu/
//if(count>4) q=96Ci_a
// siteStop(); C}+(L3Z
} jriliEz;f
ia?8Z"&lK
B'~.>,fg
System.err.println("文件下载结束！"); A;2?!i#f
} F}sfk}rp
catch(Exception e){e.printStackTrace ();} [0J0<JnK
} R \`,Q'3
\UNw43EL
n'M}6XUw
//获得文件长度 [=LQ,e$r7
public long getFileSize() mg#+%v
{ JNMZn/
int nFileLength = -1; 2OK%eVba
try{ t3bN PK^
URL url = new URL(siteInfoBean.getSSiteURL()); b,SY(Ce~g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C/]0jAAE7
httpConnection.setRequestProperty("User-Agent","NetFox"); W}T+8+RU
wl9E
8.9S91]=
int responseCode=httpConnection.getResponseCode(); "J[Crm
if(responseCode>=400) ,Zs-<e"
{ :[AW
processErrorCode(responseCode); 0eUsvzz15
return -2; //-2 represent access is error \ u5%+GA-:
} }1(F~6RH
bLf }U9
~~yo& ]
String sHeader; M4')gG;
!JrVh$K
qU=$ 0M
for(int i=1;;i++) F;MFw2G
{ M+nz~,![
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >TtkG|/U-T
//Utility.log(in.readLine()); -y$|EOi?
sHeader=httpConnection.getHeaderFieldKey(i); tWc!!Hf2j
if(sHeader!=null) @-u/('vpB
{ K3\U'bRO
if(sHeader.equals("Content-Length")) nwV\[E
{ %X#Wc:b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [>6:xGSe9X
break; d3Y#_!)
} 'f5,%e2#
} ]2Lwd@
else [qid4S~r,&
break; vT[%*)`
} \UN7lDH
} c()F%e:n
catch(IOException e){e.printStackTrace ();} b`%/*
catch(Exception e){e.printStackTrace ();} f+gyJ#R`
*+Q,b^N
8 Z#)Xb4
Utility.log(nFileLength); h^[K= J
BBy/bc!
[nflQW6
return nFileLength; =zI eZ7
} b]*9![_
<EpP;
(u$Q
//保存下载信息（文件指针位置） m2VF}% EIr
private void write_nPos() 2&5"m;<
{ {mueP6Gz@J
try{ (obeEH5J
output = new DataOutputStream(new FileOutputStream(tmpFile)); }HXNhv-K
output.writeInt(nStartPos.length); ]M= 3Sn8}
for(int i=0;i<nStartPos.length;i++) =">O;L.xj
{ .eJ4F-V
// output.writeLong(nPos); Vh'H5v^
output.writeLong(fileSplitterFetch.nStartPos); +hKQha!*
output.writeLong(fileSplitterFetch.nEndPos); j;<;?IW
} RCgs3JIE+2
output.close(); ,=z8aiUu
} w9z((\5
catch(IOException e){e.printStackTrace ();} =|uX?
catch(Exception e){e.printStackTrace ();} WFLT[j!1
} [l'~>
cV)C:!W2
AA yzT*^
//读取保存的下载信息（文件指针位置） UyIjM;X
private void read_nPos() JNk ]$ xz
{ aA0aW=R
try{ VJJw"4DJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); V^.~m;ETu]
int nCount = input.readInt(); hv7!x=?8
nStartPos = new long[nCount]; cH"M8gP#
nEndPos = new long[nCount]; ggX'`bK
for(int i=0;i<nStartPos.length;i++) 9<-AukK m
{ tjO||]I
nStartPos = input.readLong(); dkRJ^~
nEndPos = input.readLong(); *crpM3fO>
} 30[?XVI&
input.close(); H VG'v>s@
} ,/JrQWgD
catch(IOException e){e.printStackTrace ();} xae}8E
catch(Exception e){e.printStackTrace ();} RI cA)I.
} hC5ivJ
GQ)hZt0
Fc42TH p
private void processErrorCode(int nErrorCode) [nYwJ
{ IXX^C}\,
System.err.println("Error Code : " + nErrorCode); Z/56JYt!~
} #!9aTp).AL
&87D.Yy^
1<fEz
//停止文件下载 '{U56^b]
public void siteStop() d) G7U$z~
{ 4$ejJaE
bStop = true; "hpK8vQ
for(int i=0;i<nStartPos.length;i++) tse(iX/D
fileSplitterFetch.splitterStop(); 8pt;''
Y@RPQPmIQ
(zye Ch
} !^G+@~U
} H9nZ%n
//负责部分文件的抓取 9 `J`(
**FileSplitterFetch.java AUxLch+"5K
*/ l0[jepmpiT
package NetFox; }=7tGqfw
&bnF{~<\
7P!/jawxb
import java.io.*; `%F.]|Y0
import java.net.*; Qe]@`Vg
I=Ws /+
1 dI
public class FileSplitterFetch extends Thread { )#i]exZ
#Rjm3#gc
)N`ia%p_]
String sURL; //File URL QQ1+uY
long nStartPos; //File Snippet Start Position ;STO!^9~
long nEndPos; //File Snippet End Position |~rDEv3
int nThreadID; //Thread's ID L{'qZ#N[
boolean bDownOver = false; //Downing is over >0:h(,?V
boolean bStop = false; //Stop identical <k/'mBDk
FileAccessI fileAccessI = null; //File Access interface d/Fjs0pt
`;5UlkVZ5
:3{@LOil^
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Og"50-
{ ObMsncn
this.sURL = sURL; uoaF(F-
this.nStartPos = nStart; p!U#53
this.nEndPos = nEnd; z15(8Y@2]
nThreadID = id; $9Y2\'w<h6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ANn{*h
} 7^as~5'&-
;Z C18@
GAtK1%nPD
public void run() :#c?`>uV
{ 4D9lZa}
while(nStartPos < nEndPos && !bStop) XC0G5rtB
{ lb`P9mbr+
x-CYG?-x
W&BwBp]K
try{ %w6> 3#e
URL url = new URL(sURL); CG$S?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); HSp*lHU
httpConnection.setRequestProperty("User-Agent","NetFox"); RE!MX>sOEq
String sProperty = "bytes="+nStartPos+"-"; H*EQ%BLW^,
httpConnection.setRequestProperty("RANGE",sProperty); :a#]"z0
Utility.log(sProperty); Y5cUOfYT
4 lJ@qhV
RAXqRP,iw
InputStream input = httpConnection.getInputStream(); %v :a
//logResponseHead(httpConnection); pRUN[[L
p5c'gziR
m!N_TOl-^
byte[] b = new byte[1024]; q;tsA"l
int nRead; (fm\kV
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) = J).(E89
{ bq<QUw=]q&
nStartPos += fileAccessI.write(b,0,nRead); "p2 $R*ie
//if(nThreadID == 1) v#YO3nD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +*!oZKm.
} H&3VPag
k[y{&f,
6~;fj+S
Utility.log("Thread " + nThreadID + " is over!"); a5L#c=
bDownOver = true; 'rp(k\pY
//nPos = fileAccessI.write (b,0,nRead); J Y %B:
} qC.jXU?rO
catch(Exception e){e.printStackTrace ();} ;QREwT~H
} zu^?9k
} pk: ruf`)
8y~ Jn~t
\QHe0?6
//打印回应的头信息 E'JVf%)
public void logResponseHead(HttpURLConnection con) zrRt0}?xl
{ I)_072^O
for(int i=1;;i++) jr"yIC_
{ <s]K~ Vo
String header=con.getHeaderFieldKey(i); ,^:Zf|V
if(header!=null) Xdq2.:\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); V{ra,a*
Utility.log(header+" : "+con.getHeaderField(header)); H<X4R
else P}DrUND
break; L1P]T4a@)
} _ CXKJ]m4
} S;i^ucAF
A<y3Tc?Q
J U}XSb
public void splitterStop() W4|1wd}.t
{ WI[6l6
bStop = true; pWbzBgM?nU
} iDp]lu
zdU<]ge
"MM7qV
} {nm#aA%,
aE1h0`OT
yY[[)
/* nHNMoA
**FileAccess.java Ny\iRU)fN
*//文件访问(定位，写) $C,f>^1
package NetFox; H Y.,f_m
import java.io.*; <4C`^p
`$G7Ia_ $]
@T?:[nPf&F
public class FileAccessI implements Serializable{ R4E0avt
.<rL2`C[c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 kOFEH!9&
RandomAccessFile oSavedFile; [WY NA-O
long nPos; _ nS';48
}Jh!B|
<*2.B~
public FileAccessI() throws IOException ehOF@IA_
{ D3;^!ln]D
this("",0); _o' jy^
} Y]&HU) u
0*B_$E06
(.<Gde#
public FileAccessI(String sName,long nPos) throws IOException X~]eQaJ
{ rS>njG;R
oSavedFile = new RandomAccessFile(sName,"rw"); |X~T</{8i
this.nPos = nPos; K )KE0/n
oSavedFile.seek(nPos); x%vt$dy*8
} b0m1O.&I_
YAC=V?U-#
i.0}qS?
public synchronized int write(byte[] b,int nStart,int nLen) IDdhBdQ
{ EOVHTDkKf
int n = -1; .6(Bf$E
try{ ?n?Ep[D
oSavedFile.write(b,nStart,nLen); lOI(+74
n = nLen; 8 x|NR?
} Vnv<]D zC
catch(IOException e) p9oru0q
{ 67/hhO
e.printStackTrace (); 2EQ:mjxk
} 2X]2;W)S;
g#9KG
wgkh}b
return n; Ju)2J?Xs5
} Il~ph9{JH
9)aXLM4Y
0-l @U{
} uAK-%Uu?
6H.D`"cj
p?0 a"5Q
/* OHp 121
**SiteInfoBean.java ra_`NsKF}
*/ fVb&=%e
package NetFox; g9GE0DbT`
lJR",_
CuT[V?^iD
public class SiteInfoBean { UKMrR9[x*
&R\ .^3
]Ol@^$8}
private String sSiteURL; //Site's URL O'$0K0k3
private String sFilePath; //Saved File's Path q,0o:nI
private String sFileName; //Saved File's Name ^[\F uSL
private int nSplitter; //Count of Splited Downloading File /_26D0}UuF
Eq~&d.j
4K[U*-\"
public SiteInfoBean() ,Z&"@g
{//nSplitter的缺省值为5 PO<4rT+B
//default value of nSplitter is 5 &qMSJ
this("","","",5); tA}O'x
} D-E30b]e
_2}i8q:
&wK%p/?
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CIj3D"
{ 1 /7H` O?
sSiteURL= sURL; [M Z'i/
sFilePath = sPath; IUbYw~f3
sFileName = sName; 2[qO;js
this.nSplitter = nSpiltter; X/2Xr(z"k
{xr4CDP
/3'-+bp^=
} uDQ d48>
uJF,:}qA
HMrS::
public String getSSiteURL() _4xX}Z;
{ Tx`;y|
return sSiteURL; sJw3o7@pg
} 9_5Fl,u z
Tj<W4+p{
Ko>pwhR}
public void setSSiteURL(String value) {p yo
{ $@}6P,mg
sSiteURL = value; #f\U3p
} vZhN% DfY
nFX8:fZ$>
\iSaxwU_
public String getSFilePath() M=`F $
{ FUvZMA$
return sFilePath; `fY~Lv{4d_
} psgXJe$
MftX~+
F>96]71 2
public void setSFilePath(String value) qZ6P(5X
{ w[~$.FM/
sFilePath = value; najd~%?Rs
} v?-pAA)ht
m~(]\
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public String getSFileName() &]16Hb~
{ }yK_2zak5i
return sFileName; A^bg*t,
} F4YCU$V
j'X]bd'
\&Mipf7a
public void setSFileName(String value) P7 H-Dw
{ ]y2(ZTNTs
sFileName = value; R1 hb-
} ]Tx8ImD#)A
VbKky1a@
mxGa\{D#y
public int getNSplitter() vd9l1"S
{ `~(KbH=]
return nSplitter; H}dsd=yO
} do+HPnfDzU
tceQn ^|<
5m=3{lBi
public void setNSplitter(int nCount) *&% kkbA
{ :PY~Cws
nSplitter = nCount; qyP@[8eH
} TStu)6%`
} TsfOod
P%ev8]2
6wqq"6w
/* b U-Cd
**Utility.java \3O#H
*/ =V/$&96Q
package NetFox; : \:jIP
O<)"kj 7
Z>wg o@z%
public class Utility { <6Y o%xt
ppM d
4 "@BbVYR
public Utility() .%M=dL>
{ %)i?\(/
p*-o33Ve
T,TKt%
} r[Qk-}@vp
DSM,dO'
//线程睡眠 kbI:}b7H
public static void sleep(int nSecond) n-#?6`>a
{ gk>A
try{ ALiA+k N
Thread.sleep(nSecond); "F7g8vu
} (9*=d_=
catch(Exception e) T]Vh]|_s
{ _`+ !,kG[
e.printStackTrace (); g%4-QCZ,
} K9mL1[B
} V2^(qpM!
{I@@i8)]
//日志 yCf*ts1
public static void log(String sMsg) Vx~[;*{,C9
{ #?@k=e\
System.err.println(sMsg); ZcYxH|Gn
} i jg'X#E
W&A22jO.1
bO>Mvf
public static void log(int sMsg) 3R !Mfz*
{ V/.Y]dN5
System.err.println(sMsg); E@}t1!E<
} S@k4k^Vg
} D`o*OlU
WID4{>G2
>/.-N
/* =4RnXZ[P0
**TestMethod.java )U6T]1
*/ $"!"=v%B
package NetFox; Zh)Qq?H
$Dxz21|P7
h:Q*T*py
public class TestMethod { 1Yo9Wf;vP
c]P`U(q9TV
Zoh2m`6
public TestMethod() IR;lt 3
{ ///xx/weblogic60b2_win.exe J-:\^uP
try{ ReE6h\j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +`r;3kH ..
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); g7EJyA
SiteFileFetch fileFetch = new SiteFileFetch(bean); Egi<m
fileFetch.start(); ssoIC
} ]uI#4t~
catch(Exception e){e.printStackTrace ();} W~$YKBW
V)mRG`L
(%rO'X
} qSlC@@.>
[>A%%
6#MIt:#
public static void main(String[] args) P5yS`v$@
{ <T>C}DGw
new TestMethod(); V2W)%c'
} |bk.gh
} ^8,HJG,!
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