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)); _lqAxWH
} HX*U2<^
for(int i=0;i<nEndPos.length-1;i++) 3$;v# P$%N
{ o!S_j^p[C
nEndPos = nStartPos[i+1]; _nq n|
} }cmL{S
nEndPos[nEndPos.length-1] = nFileLength; G[,VPC=
} epm|pA*
} b6BIDuRb
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42LV>X#i
//启动子线程 6d8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; SUhP e+
for(int i=0;i<nStartPos.length;i++) tjt#VFq?
{ m#'9)%t!J
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A79SAheX#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -E"o)1Pj6C
nStartPos,nEndPos,i); c[q3O**
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6fyW6xv[,
fileSplitterFetch.start(); ?GZs5CnS
} HjD= .Q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $y}Tbm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ljmHX2p
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", '9XwUQx
nEndPos = " + nFileLength); h,G$e|[?
// fileSplitterFetch[nPos.length-1].start(); IYN`q'%|
tWIhbt
Y7HWf
//等待子线程结束 kfV}w,
//int count = 0; '?t{-z,
//是否结束while循环 t-/^O
boolean breakWhile = false; IRB;Q(Z
`0N/ /Q
Gr?gHAT
while(!bStop) _`58G#z
{ tnntHQ&b
write_nPos(); 4V5*6O9(u
Utility.sleep(500); 5Z{[.&x
breakWhile = true; Ycm1 _z
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1|CO>)*D
for(int i=0;i<nStartPos.length;i++) je\UfEo%
{ mi?Fy0\
if(!fileSplitterFetch.bDownOver) s!Vtwp9
{ V,}cDT>
breakWhile = false; i8F~$6C
break; 1'U-n{fD
} :+n7oOV
} 5Jp>2d
if(breakWhile) ?##GY;#
break; oT w1w
O"GzeEY7
ZN^Q!v
//count++; EBm\rM8
//if(count>4) w*0T"hK
// siteStop(); U*t`hn-xs
} f,*e?9@;s
y|ZJ-[qg
;Lx5r=<Hx
System.err.println("文件下载结束！"); ;F5%X\t-
} 6}0#({s:R
catch(Exception e){e.printStackTrace ();} WqAP'x 1
} Bvwk6NBN
6|9fcIh]B
;(A'XA4 6N
//获得文件长度 qabM@+m[
public long getFileSize() eZHi6v)i
{ <JlKtR&nSo
int nFileLength = -1; fO+;%B
try{ va)\uXW.N
URL url = new URL(siteInfoBean.getSSiteURL()); ~2H)#`\ac8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Cv3H%g+as
httpConnection.setRequestProperty("User-Agent","NetFox"); ZtiOf}@i\
&E~7ty'
&fWZ%C7|jC
int responseCode=httpConnection.getResponseCode(); 71eD~fNdx
if(responseCode>=400) 8G=4{,(A
{ `YJ`?p
processErrorCode(responseCode); );C !:?
return -2; //-2 represent access is error b^ZrevM
} :&]%E/
: f Wh7X3
yl*S|= 8;k
String sHeader; U i;o/Z3
4V=dD<3m
h&XyMm9C
for(int i=1;;i++) |Ia46YS
{ v^pE=f*/
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h^4oy^9
//Utility.log(in.readLine()); ,Tpds^
sHeader=httpConnection.getHeaderFieldKey(i); _-^@Jx[
if(sHeader!=null) {.sF&(e
{ zOcMc{w0
if(sHeader.equals("Content-Length")) h`)r :a7
{ 7dLPy[8";t
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); NWf!c-':
break; #nnP.t m
} @|M10r9E
} nt4>9;
else +IU]=qS
break; $`i&\O2*
} VFyt9:a
} IV\@GM:ait
catch(IOException e){e.printStackTrace ();} m{' q(w}
catch(Exception e){e.printStackTrace ();} }b44^iL$9y
I6UZ_H'E
15870xS
Utility.log(nFileLength); ^rI&BN@S
6oC(09
C>LkU|[
return nFileLength; #3.\}d)
} ms~ mg:
V'_^g7}l&
4Hu.o7
//保存下载信息（文件指针位置） ^0VI J)y
private void write_nPos() 6(wpf^br2
{ 1iz\8R:0
try{ 2o,%O91p
output = new DataOutputStream(new FileOutputStream(tmpFile)); .NabK
output.writeInt(nStartPos.length); U7Ps2~x3
for(int i=0;i<nStartPos.length;i++) :Y"f.>
{ 4ed( DSN
// output.writeLong(nPos); qsJo)SA
output.writeLong(fileSplitterFetch.nStartPos); KzhldMJ^zq
output.writeLong(fileSplitterFetch.nEndPos); @wB$qd;v
} O,7P6
output.close(); #<)u%)`
} EF}Z+7A
catch(IOException e){e.printStackTrace ();} \wMr[_LW
catch(Exception e){e.printStackTrace ();} H>VuUH|
} gB?#T
. a~J.0co
@]~\H-8
//读取保存的下载信息（文件指针位置） "#JRw
private void read_nPos() Pocm.
{ DBOz<|
try{ .@R{T3=Q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h:l\kr|9
int nCount = input.readInt(); 2;A].5>l
nStartPos = new long[nCount]; Rj-<tR{
nEndPos = new long[nCount]; ]NN9FM.2b/
for(int i=0;i<nStartPos.length;i++) gXG1w>
{ C8i}~x<
nStartPos = input.readLong(); s`&8tP
nEndPos = input.readLong(); FFPO?y$
} T*z >A
input.close(); 2@=JIMtc
} a(bgPkPP
catch(IOException e){e.printStackTrace ();} RXh/[t+
catch(Exception e){e.printStackTrace ();} bA1uh]oB
} \4mw>8wA
sz_|py?0
55fV\3F|R
private void processErrorCode(int nErrorCode) .0nL;o
{ 'AHI;Z~Gk
System.err.println("Error Code : " + nErrorCode); p9Ks=\yvL
} 7` &K=( .
m"NZ;*d'
Qu!Lc:oM?
//停止文件下载 nKch_Jb
public void siteStop() 8LB+}N(8f
{ |eJ4"OPC
bStop = true; lQldW|S>
for(int i=0;i<nStartPos.length;i++) oC"c%e8
fileSplitterFetch.splitterStop(); *l^h;RSx
<$_B J2Z
10{ZW@!7
} +:;r} 7Zh
} GKSfr8US4
//负责部分文件的抓取 8 yQjB-,#
**FileSplitterFetch.java 2BEF8o]Np
*/ 90&ld:97
package NetFox; )9,9yd~SI
GAV|x]R
Ydh]EO0'
import java.io.*; 36e!je
import java.net.*; hQvSh\p
l$z\8]x
cOq^}Ohan
public class FileSplitterFetch extends Thread { _da>=^hFJ
Kr!8H/Z
pX+`qxF\
String sURL; //File URL Y;4nIWe JL
long nStartPos; //File Snippet Start Position O:WFh;c
long nEndPos; //File Snippet End Position fHdPav f,S
int nThreadID; //Thread's ID )EcE{!H6+
boolean bDownOver = false; //Downing is over Ag^Cb'3X
boolean bStop = false; //Stop identical _m#M^<0n
FileAccessI fileAccessI = null; //File Access interface Yu`b[]W
ng^`s}?o
Z[s{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException G ,An8GR%&
{ +2!F6"hP
this.sURL = sURL; Tt<Ry'Z$3
this.nStartPos = nStart; :VX?j3qW
this.nEndPos = nEnd; }hv>LL
nThreadID = id; 22)2olU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 s`U.h^V
} q0,Diouq
*^ g7kCe(
T]Pp\6ff
public void run() IMpEp}7
{ F_$eu-y
while(nStartPos < nEndPos && !bStop) MPhO#;v
{ !O~EIz
y4^6I$M7V
<:fjWy
try{ dnSjXyjFB
URL url = new URL(sURL); a39Kl_\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "WV]| TS"]
httpConnection.setRequestProperty("User-Agent","NetFox"); O|}97a^
String sProperty = "bytes="+nStartPos+"-"; 8(&Jy RT
httpConnection.setRequestProperty("RANGE",sProperty); Tl6%z9rY@
Utility.log(sProperty); FhVi|Va
"hdcB 0
!c(B c^
InputStream input = httpConnection.getInputStream(); 3V>2N)3`A
//logResponseHead(httpConnection); 9l5l"Wj&
^(r?k_i/
Yh\} i
byte[] b = new byte[1024]; |f#~#Y2v
int nRead; CXwDG_e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6lpfk&
{ 7g^=
nStartPos += fileAccessI.write(b,0,nRead); OQIQ
//if(nThreadID == 1) bsO78a~=P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Ii_X^)IL(
} x >hnH{~w
ep* (
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Utility.log("Thread " + nThreadID + " is over!"); dcew`$SJp
bDownOver = true; h(*!s`1
//nPos = fileAccessI.write (b,0,nRead); { AdPC?R`
} :80!-F*\
catch(Exception e){e.printStackTrace ();} GdVq+,Ge
} C(qqGK{
} uU=O0?'zq
x<W`2Du
Y;JV9{j
//打印回应的头信息 <iDqt5)N
public void logResponseHead(HttpURLConnection con) jl YnV/ ]
{ `Hld#+R
for(int i=1;;i++) O RAKg.49
{ of!Bz
String header=con.getHeaderFieldKey(i); Rrmk\7/
if(header!=null) {p@uH<)
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ve;#o<
Utility.log(header+" : "+con.getHeaderField(header)); a/Z >-
else }c?/-ab>
break; #&a-m,Y$sx
} 9&a&O Z{
} |7KW'=O
PZmg7N
/2Q@M>
public void splitterStop() Vw0cf;
{ u?6L.^Op
bStop = true; gx~79;6
} {U/a h2*
0 UdAF
b.V\EOk
} 1D159NLB
7)aitDD
AvnK?*5!@
/* MW*@fl<@?M
**FileAccess.java +c$]Q-(
*//文件访问(定位，写) h.+{cOA;n
package NetFox; No#1Ikw
import java.io.*; ,5J-C!C
rjqQWfShY
Wm!lWQu7
public class FileAccessI implements Serializable{ BBnW0vAZ*
,w&8 &wj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zG)XB*c
RandomAccessFile oSavedFile; j}}:&>;
long nPos; z9OhY]PPF
)bN|*Bw3
) inhPd
public FileAccessI() throws IOException FaS}$-0
{ ti$d.Kc(
this("",0); p!5=1$
} {nTQc2T?;
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-ZwQL="t
public FileAccessI(String sName,long nPos) throws IOException k/[*Wz$W
{ "#Ov!t
oSavedFile = new RandomAccessFile(sName,"rw"); ]gI>ay"\QA
this.nPos = nPos; pt[H5
oSavedFile.seek(nPos); MR:GH.uM:
} mqxgrb7
T4MB~5,i
~gU.z6us
public synchronized int write(byte[] b,int nStart,int nLen) >b9nc\~
{ ]*b}^PQM^
int n = -1; )Lt|]|1B{
try{ )\fAy
oSavedFile.write(b,nStart,nLen); 1 ?X(q
n = nLen; S ykblP37
} 6;"^Id
catch(IOException e) ;\~{79c
{ TTB1}j+V6
e.printStackTrace (); a|aRUxa0"
} H{}0-0o
f`Km ctI
lFvRXV^+f
return n; :6R0=oz
} hF`e>?bN
{c5%.<O
OT-!n
} Mle@.IIT
qbu>YTj
=fA*b
/* MLD-uI10{
**SiteInfoBean.java `U:W(\L
*/ :5 XNV6^|
package NetFox; d:KUJ Y.
S<), ,(
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public class SiteInfoBean { Vy*&po[
pPr/r&r
<?|v-(E
private String sSiteURL; //Site's URL H"v3?g`S%
private String sFilePath; //Saved File's Path r0 %WGMk2
private String sFileName; //Saved File's Name jTVh`d<N
private int nSplitter; //Count of Splited Downloading File k&Z3v.
d GEMrjx
];@"-H
public SiteInfoBean() Fqtgw8
{//nSplitter的缺省值为5 G)qNu}
//default value of nSplitter is 5 @ s
this("","","",5); 9rhIDA(wc
} Co e q<
'n'83d)z
Rx';P/F0C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) (W*~3/@D
{ "YIrqk
sSiteURL= sURL; OGmOk>_
sFilePath = sPath; X6_m&~}15
sFileName = sName; Vs>/q:I
this.nSplitter = nSpiltter; ]-
5p9zl=mT
hD OEJ
} {/f\lS.5g
Xy_ <Yqx}
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public String getSSiteURL() :\ %.x3T'
{ hg8gB8Xq
return sSiteURL; \U^0E> d
} R-xWZRl>
4]\f}
lWYZAF>?Ym
public void setSSiteURL(String value) JE~ci#|!
{ `Qzga}`"]
sSiteURL = value; FcR(uv<
} iUcDj:
WU}?8\?U%
EH;w <LvT
public String getSFilePath() ,^dyS]!d$
{ l.tNq$3pS
return sFilePath; }=kf52Am,}
} x50,4J%J'r
L\@SX?j
MGUzvSf
public void setSFilePath(String value) {~=Edf
{ #lA8yWxr
sFilePath = value; b>R/=tx
} }Qjp,(ye
{fsU(Jj\
IvLo&6swW
public String getSFileName() .]_Ye.}
{ igNZe."V
return sFileName; 3?Ckk{)&
} n-q
d ]LF5*i
@^Tof5?F?
public void setSFileName(String value) "tuBfA+f
{ AF5$U8jf
sFileName = value; A?{ X5`y
} "zSi9]j
YmP`Gg#>p
&m=Xg(G~c
public int getNSplitter() 8nOMyNpy~M
{ cnm&oC 6
return nSplitter; !mFx= +
} )+]8T6~ N
; z_ZZ(W
l#P)9$%
public void setNSplitter(int nCount) Rpit>
{ x\qS|q\N
nSplitter = nCount; odxsF(Q0p
} J8|F8dcz
} Yk',a$.S
O[O`4de9
:+;AXnDM~
/* D[.; H)V
**Utility.java bH}6N>Fp
*/ *hI
package NetFox; 0T,Qn{
V|.3Z\(
:O:Rfmr~
public class Utility { p8<Y5:`
V"n0"\k,
eto3dJ!R
public Utility() y(&JE^GfX
{ p"4i(CWGS
x2B~1edf
2`(-l{3
} FoM4QO
(uG.s%I
//线程睡眠 olPV"<;+pO
public static void sleep(int nSecond) T1bPI/
{ .uzg2Kd_
try{ c)8V^7=Q
Thread.sleep(nSecond); JpN]j`
} /3D!,V,
catch(Exception e) eCB(!Y|
{ u9>zC QRO
e.printStackTrace (); Z&W|O>QTl
} T^h;T{H2
} sGIY\%
5Cxh>,k
//日志 ?29zcuRaru
public static void log(String sMsg) }IvJIr
{ UF)rBAv(/
System.err.println(sMsg); <VV./W8e9
} 6zs&DOB
q;3,}emg
? lC. Pq
public static void log(int sMsg) 4fBgmL
{ Tj@}O:q7:
System.err.println(sMsg); Ms5m.lX
} K1>.%m
} jR7 , b5
bF %#KSVw
YK*2
/* 8[i#x|`g
**TestMethod.java g~_cYy
*/ D+{h@^C9Z
package NetFox; ~[XDK`B
QC0^G,9.
cSCO7L2E18
public class TestMethod { DZ~w8v7V
}h<\qvCcU
"UVqkw,vt
public TestMethod() X0 &1ICZ
{ ///xx/weblogic60b2_win.exe G1M}g8 ]h
try{ [0CoQ5:d?&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); RC Fb&,51
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); N'R^S98x
SiteFileFetch fileFetch = new SiteFileFetch(bean); ~/1kCZB
fileFetch.start(); y [e$
} :~loy'
catch(Exception e){e.printStackTrace ();} >XP]NY}Po[
i'J.c4
kRNr`yfN
} 1\q(xka{
Sr~zN:wn
}Q_IqI[7
public static void main(String[] args) yrO'15TB
{ FT73P0!8.
new TestMethod(); i_ws*7B<
} z<c^<hE:l
} %Rv&VFg
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