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)); FZH-q!"^cK
} Qne0kB5m
for(int i=0;i<nEndPos.length-1;i++) fy`+Efuj
{ h mds(lv7
nEndPos = nStartPos[i+1]; z|Ap\[GS
} 7pP+5&*
nEndPos[nEndPos.length-1] = nFileLength; f0u56I9
} z(rK^RT
} "9%qbMB
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KXq_K:r?
//启动子线程 P2t_T'R}
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~GA8_B
for(int i=0;i<nStartPos.length;i++) aLYLd/ KV
{ e62y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _0.pvQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6< >SHw
nStartPos,nEndPos,i); 6{8/P'@/Zz
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C 0>=x{,v
fileSplitterFetch.start(); /'\;8A$J`
} W_%W%i|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r^Y~mq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); M7vj^mt?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C38%H
nEndPos = " + nFileLength); Mc:bU
// fileSplitterFetch[nPos.length-1].start(); xHe^"LL
06jMj26!
~{P:sjsU
//等待子线程结束 I-bF{
//int count = 0; !LiQ 1`V{
//是否结束while循环 rH.gF43O:
boolean breakWhile = false; k2.G%]j
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'#<> "|
while(!bStop) jq[x DwPG
{ Oy%Im8.-A#
write_nPos(); 7`dY1.rq
Utility.sleep(500); 'in@9XO
breakWhile = true; e3g_At\
#%8 w
nj
for(int i=0;i<nStartPos.length;i++) Cg3ODfe
{ $_FZn'Db6
if(!fileSplitterFetch.bDownOver) jtCZfFD?
{ HCazwX
breakWhile = false; ;ctU&`
break; ;'^, ,{
} b2s~%}T
} "H?QqrKx
if(breakWhile) ]u0Jd#@
break; {*$9,
GS4_jvD-
'evv,Q{87
//count++; UJn/s;$.e
//if(count>4) nvH|Ngg Q
// siteStop(); /WYh[XKe
} "Yby
KuXkI;63J>
{(Fe7,.S3
System.err.println("文件下载结束！"); eO[c lB
} ;RHNRVP
catch(Exception e){e.printStackTrace ();} !DcX8~~@
} RHI&j~
V.2[ F|P;3
_Ex|f5+
//获得文件长度 hy!6g n
public long getFileSize() R&Ci/
{ 6pm~sD
int nFileLength = -1; q% EC
try{ aS/`A
URL url = new URL(siteInfoBean.getSSiteURL()); ]EN&SWh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); uA%Ts*aN
httpConnection.setRequestProperty("User-Agent","NetFox"); t7^D-l
P7r4ePtLk{
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int responseCode=httpConnection.getResponseCode(); iaRR5D-
if(responseCode>=400) 9|3o<
{ =:/>6H1x
processErrorCode(responseCode); |X3">U +-
return -2; //-2 represent access is error rJV?)=Z
} ls @5^g
]]/lC
(OqHfv
String sHeader; ! Rvn'|!
choL%g}
M=[th
for(int i=1;;i++) [%~^kq=|
{ h.^o)T
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); OL9]*G?F
//Utility.log(in.readLine()); TvM24Orct
sHeader=httpConnection.getHeaderFieldKey(i); 9U'[88
if(sHeader!=null) pl\b-
{ xlw 2g<s
if(sHeader.equals("Content-Length")) r=$gT@
{ J7n5Ps\M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =G>.-Qfs
break; )!a$#"'
} fYn{QS?
} WW6yFriuW
else 9P0yv3
break; V{GXc:=
} l5HWZs^
} lY,/W
catch(IOException e){e.printStackTrace ();} >h%\HMKk
catch(Exception e){e.printStackTrace ();} !.X_/$c
\xeVDKJH+n
7}o6_i
Utility.log(nFileLength); !-RwB@\
h!Y?SO.b
`j:M)2:*y
return nFileLength; tN}c0'H
} QT;Va#a
gVA; `<
xE1rxPuq)d
//保存下载信息（文件指针位置） XNlhu^jh
private void write_nPos() 6F-JK1i
{ DB~MYOX~
try{ pns+y
output = new DataOutputStream(new FileOutputStream(tmpFile)); 6Hn)pD#U
output.writeInt(nStartPos.length); (H1lqlVWV#
for(int i=0;i<nStartPos.length;i++) B52H(sm
{ HL8(lPgS
// output.writeLong(nPos); *:j-zrwu&
output.writeLong(fileSplitterFetch.nStartPos); r w\D>}\
output.writeLong(fileSplitterFetch.nEndPos); 5&*zY)UL
} xx0k$Dqt2I
output.close(); ~v\hIm3=m
} 3&9zGy{V+
catch(IOException e){e.printStackTrace ();} 3G.r-
catch(Exception e){e.printStackTrace ();} ^Xa*lR 3
} 1ys(v
h"8QeX:((
Wxs>osq
//读取保存的下载信息（文件指针位置） ctK65h{Eo
private void read_nPos() x5PPu/
{ ZYDWv/u
try{ &N9IcNP
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); D2)i3vFB
int nCount = input.readInt(); 117c,yM0
nStartPos = new long[nCount]; /sV?JV[t
nEndPos = new long[nCount]; &M=3{[
for(int i=0;i<nStartPos.length;i++) #!L%J<MX
{ w49{-Pp[
nStartPos = input.readLong(); )^";BVY
nEndPos = input.readLong(); x,f>X;04
} Br&^09S
input.close(); "8?TSm8
} uR^.
catch(IOException e){e.printStackTrace ();} -~} tq]
catch(Exception e){e.printStackTrace ();} wsI5F&R,
} o"\{OX
L&'l3|
b@!:=_Mr
private void processErrorCode(int nErrorCode) DU`v J2
{ NFV_+{X\
System.err.println("Error Code : " + nErrorCode); Y!it!9
} *V-ds8AQ
5v+L';wx[T
([tG y
//停止文件下载 D$mf5G &
public void siteStop() q^%5HeV 2
{ 4a?r` '
bStop = true; ozuIwzi7N
for(int i=0;i<nStartPos.length;i++) hRLKb}
fileSplitterFetch.splitterStop(); "\<P$&`HA
d9|T=R
HGb.656r
} /0l-mfRr
} 0NrTJ R`
//负责部分文件的抓取 ]Cr]Pvab{
**FileSplitterFetch.java ^7<[}u;qF
*/ >R#9\/s
package NetFox; LjCykk
IX?@~'
j37:
import java.io.*; 9[Y*k^.!
import java.net.*; @EYK(QS-
&jFKc0\i@
Z<I[vp6{
public class FileSplitterFetch extends Thread { J(^ >?d'
[C2kK *JZ
l=,.iv=W
String sURL; //File URL c9|I4=_K
long nStartPos; //File Snippet Start Position D?%e"*>
long nEndPos; //File Snippet End Position tfsh!)u?
int nThreadID; //Thread's ID K/~Y!?:Jr
boolean bDownOver = false; //Downing is over ti+pUlVrM
boolean bStop = false; //Stop identical C5cFw/',
FileAccessI fileAccessI = null; //File Access interface ;*_I,|A:Xr
NPP3(3C
SK}HXG{?
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1ZKz3)K
{ I51M}b,[d
this.sURL = sURL; ]yw_n^@
this.nStartPos = nStart; ^fG`DjA)
this.nEndPos = nEnd; KzIt
nThreadID = id; EmF]W+!z%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 BSjbnnW}"
} [GOX0}$?
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j\nE8WH
public void run() E*h0#m|)
{ on6<l
while(nStartPos < nEndPos && !bStop) zV6AuUIt
{ ]<Z&=0i#9
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try{ )H.ubM1
URL url = new URL(sURL); vI4%d,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3KDu!w@
httpConnection.setRequestProperty("User-Agent","NetFox"); 4S^
String sProperty = "bytes="+nStartPos+"-"; u!m,ilAnd
httpConnection.setRequestProperty("RANGE",sProperty); =%:JjgKc*t
Utility.log(sProperty); 0c%@e2(N
Qfwwh`;
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InputStream input = httpConnection.getInputStream(); fmatc#G
//logResponseHead(httpConnection); {hlT`K
cw*(L5bu
rE!G,^_{
byte[] b = new byte[1024]; V]+o)A$
int nRead; h9,wiT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) [_B+DD=}
{ ,?P8m"
nStartPos += fileAccessI.write(b,0,nRead); Sn_z
//if(nThreadID == 1) mrhsKmH
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); C}t+t
} #L|JkBia
& y#y>([~
aNuZ/9O
Utility.log("Thread " + nThreadID + " is over!"); D}=/w+
bDownOver = true; U[K0{PbY
//nPos = fileAccessI.write (b,0,nRead); N]3-L`t
} '8]|E
catch(Exception e){e.printStackTrace ();} AH"g^ gw~T
} BH.:_Qrbh[
} O>)n*OsS
6Cop#kW#
awj}K
//打印回应的头信息 hfl%r9o
public void logResponseHead(HttpURLConnection con) *K0j5dx
{ S,d ngb{
for(int i=1;;i++) I@y2HxM
{ 4OqE.LFu
String header=con.getHeaderFieldKey(i); F&nMI:h7
if(header!=null) ]4LT#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); LaEX kb*s
Utility.log(header+" : "+con.getHeaderField(header)); mGMinzf
else te!]9rR
break; dQWA"6?i
} _oMs `"4K
} 6T} CPDRq
/ y":/"h
b3CspBgC
public void splitterStop() )cv0$
{ #J<`p
bStop = true; Os]!B2j14
} 2>_brz|7:|
p;c_<>ws-Y
],fwZd[t
} Wf+Cc?/4
V5(tf'
3^iQe"P%a@
/* 2yCd:wg
**FileAccess.java "p6:ekw
*//文件访问(定位，写) /v|68x6
package NetFox; 8KGv?^M 6W
import java.io.*; Ztpm_P6
9$4/frd
an[3vKb
public class FileAccessI implements Serializable{ *Wuctu^9
L(!!7B_,
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 .9[8H:Fe
RandomAccessFile oSavedFile; oE|u;o
long nPos; 3ZJagJ\O
q!9v}R3(
tl,x@['p`
public FileAccessI() throws IOException J!TK*\a2
{ M#8Ao4 T
this("",0); J:TI>*tn
} '#An+;x{
,N@Icl
"DcueU#!
public FileAccessI(String sName,long nPos) throws IOException r{6B+3J
{ l]58P
oSavedFile = new RandomAccessFile(sName,"rw"); ym,Ot1
this.nPos = nPos; A86lyBDQ*
oSavedFile.seek(nPos); [&O:qaD^
} l_q>(FoqA
]rX?n
$=QGua V
public synchronized int write(byte[] b,int nStart,int nLen) *l'$pJ X
{ JXy667_
int n = -1; I?B,rT3h
try{ C$re$9U
oSavedFile.write(b,nStart,nLen); 3 Q%k(,
n = nLen; 3PR7g
} m 'H
catch(IOException e) PuoJw~^h
{ X#NeB>~
e.printStackTrace (); (!&O4C5
} Sy0s`\[
l<MCmKuYp
"a`0w9Mm}
return n; 6x3Ew2
} vJjj+:
Vx4pP$S
<~8f0+"
} \#oV<MR
1eR{~ ,
Y;5^w=V
/* nF[eb{GR`
**SiteInfoBean.java YU\t+/b
*/ uKAHJ$%
package NetFox; HE<%d
&I'F-F;
XxU}|jTO#
public class SiteInfoBean { q\pc2Lh?^
h|>n3-k|p
D '_#?%3^
private String sSiteURL; //Site's URL 1bAp{u&
private String sFilePath; //Saved File's Path 7a.#F]`
private String sFileName; //Saved File's Name {]m e?I
private int nSplitter; //Count of Splited Downloading File P>,D$-3
xupdjT%4
=&G|} M
public SiteInfoBean() #7:9XID /
{//nSplitter的缺省值为5 c+M@{EbuN
//default value of nSplitter is 5 gwjv&.T6^
this("","","",5); "'dC>7*<
} #^[N4uV
rTiuQdvo
Q-%=ZW Z
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) x,*t/nzR
{ b,V=B{(~
sSiteURL= sURL; &T.P7nJ=
sFilePath = sPath; T`DlOi]Z_
sFileName = sName; -Z&{$J
this.nSplitter = nSpiltter; Xg#([}b
8[p6C Jl)
)8>f
} b#'a4j-u
XD>@EYN<X
13@| {H CB
public String getSSiteURL() oRF"[G8BV
{ R20GjWy=
return sSiteURL; i-W2!;G
} +FK<j;}C7
}Q(I&uz
a8U2c;
public void setSSiteURL(String value) JKbB,
{ t$5]1dY$X
sSiteURL = value; B{KD ]
} xeh|u"5
dgD%I
hiM!htc;M
public String getSFilePath() xfSvvCy
{ WSwmX3rn
return sFilePath; a'~y'6
} mMWNUkDq
GlZDuU
kniMXeiu
public void setSFilePath(String value) #8|NZ6x,
{ l.)!jWY
sFilePath = value; E6)mBAE
} #| Po&yu4R
5q>u }J
bV,R*C
public String getSFileName() /_(Dq8^g@
{ Ut=y`]F
return sFileName; K;lC#
} R6Lr]H
1 j8,Zrg1
B!anY}/U
public void setSFileName(String value) V [>5
{ vX%gcs/@
sFileName = value; ']D( ({%g
} 9tQk/niMM5
i[n1}E.@
aQ. \!&U
public int getNSplitter() p04w83 jX
{ jnY4(B
return nSplitter; F6/bq/s
} `rV,<
VPbNLi
'r CR8>k
public void setNSplitter(int nCount) x.RZ!V-
{ +`FY
nSplitter = nCount; M}u2aW2]X
} v/dcb%
} [u:_Jqf-
d8po`J#nb
$Izk]o;X~
/* ]&>)=b!,
**Utility.java 5KzU&!Zh9
*/ %LyB~X
package NetFox; XJ+sm^`vOf
lki(_@3
,D1QJPM
public class Utility { b3H;Ea?^^<
<U*d
:&MiO3#+
public Utility() A6VkVJZx
{ rxA<\h,A
.:}\Z27-c
.755-S
} ~7v^7;tT
R.@GLx_zpQ
//线程睡眠 E_P]f%
public static void sleep(int nSecond) <Bwu N,}
{ O{PRK5^h
try{ )? xg=o/?
Thread.sleep(nSecond); cQjJ9o7
} %?seX+ne
catch(Exception e) &IPT$=u
{ & CgLF]
e.printStackTrace (); ^*W3{eyi(L
} w}iflAnjq
} PNq#o%q
U4gZW]F
//日志 kI]1J
public static void log(String sMsg) m(Oup=\%b}
{ %2.T1X%!
System.err.println(sMsg); 1D$k:|pP~
} n(L {2r
Y:wds=lA
8^T' a^Wt
public static void log(int sMsg) F]&9Lp} "
{ shD$,! k
System.err.println(sMsg); *UTk. :G5
} V}("8L
} A/MOY@%G
aaBBI S
ny}?+&K
/* x?k6ek
**TestMethod.java Rj8l]m6U9
*/ >U17BGJ.
package NetFox; eu~;G H
w v1R ]3}
ixp%aRRP
public class TestMethod { .]" o-(gB
*]rV,\z:
E^rN)
public TestMethod() wL{Qni3A
{ ///xx/weblogic60b2_win.exe OSBE5
try{ h0GXN\xI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); S+He
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); E yNCky
SiteFileFetch fileFetch = new SiteFileFetch(bean); U_:/>8})d
fileFetch.start(); _C##U;e!
} ]$7|1-&Y
catch(Exception e){e.printStackTrace ();} Aam2Y,B
yVW)DQ4?
<fP|<>s$@1
} Ft07>E$/Q^
F:n7yey
D;Z\GnD
public static void main(String[] args) 5!wa\)wY
{ 1(-)$m8}
new TestMethod(); :/u EPki
} Ts.61Rx
} TG!sck4/-Q
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