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)); %f\{ ]
} rwFR5
for(int i=0;i<nEndPos.length-1;i++) sF]v$kq
{ %0INtq
nEndPos = nStartPos[i+1]; &d`Umm]
} |8&AsQd
nEndPos[nEndPos.length-1] = nFileLength; ~wDmt
} ?+GbPG~
} M! gX4
J"|)?$d]z
yk#yrxM
//启动子线程 n=r}jRH1
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; s8}:8
for(int i=0;i<nStartPos.length;i++) "*laY<E
{ <.$<d
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), v6oPAqj,r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), D[7K2G+
nStartPos,nEndPos,i); BQSA;;n]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qh0)~JL4
fileSplitterFetch.start(); ,.]e~O4R
} BArsj
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nen6!bw4
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); E{T\51V]%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GWjKZ1p
nEndPos = " + nFileLength); XZcsx
// fileSplitterFetch[nPos.length-1].start(); #i ?@S$
N$pwTyk
|C'w] QYm
//等待子线程结束 /2>-h-zBjw
//int count = 0; 7zr\AgV9
//是否结束while循环 rRcfZZ~` M
boolean breakWhile = false; y;0.P?Il"
D\(,:_ge
78+H|bH8
while(!bStop) MP[v 9m@
{ Qu!\Cx@
write_nPos(); eN/sW!:P|
Utility.sleep(500); {9;~xxTo
breakWhile = true; au"HIyi?k
"c!s\iuBU
dtA- 4Ndm
for(int i=0;i<nStartPos.length;i++) ^Q!:0D*
{ dwrc"GK!o
if(!fileSplitterFetch.bDownOver) .~v~~VL1NS
{ ;zs*Zd7h M
breakWhile = false; >]:R{1h
break; zIF &ZYP
} [w=x0J&
} bQXxb(^
if(breakWhile) 6$ IXER
break; C$*`c6R
[7<X&Q
zmr=iK
//count++; ^+`vh0TPQ
//if(count>4) t)cG_+rJ
// siteStop(); G]P4[#5
} :U)e 8
Lom%eoH)
32~Tf,
System.err.println("文件下载结束！"); e"r}I!.
} /lr RbZ
catch(Exception e){e.printStackTrace ();} KG>.7xVWV7
} !Q.c8GRUQ
V.y+u7<3}
W3<O+S&
//获得文件长度 KNY<"b
public long getFileSize() 0p2 0Rt
{ QMtt:f]?i
int nFileLength = -1; yqejd_cd
try{ 'Dat.@j
URL url = new URL(siteInfoBean.getSSiteURL()); LWVO%@)w
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wW%I <M
httpConnection.setRequestProperty("User-Agent","NetFox"); `W]a @\EYA
T{uktIO/
30DpIkf
int responseCode=httpConnection.getResponseCode(); /;OJ=x3i
if(responseCode>=400) L+I[yJY:!
{ m9L+|r
processErrorCode(responseCode); 7y[B[$P
return -2; //-2 represent access is error _Fz)2h,3
} l$zNsf.
,1~Zqprn
//J:p,AF
String sHeader; ]G1j\wnF
A:D\!5=
6,@M0CX
for(int i=1;;i++) G!rcY5!J
{ 3\4Cg()
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); J&3;6I &
//Utility.log(in.readLine()); mceSUKI;L
sHeader=httpConnection.getHeaderFieldKey(i); Ce:R p?
if(sHeader!=null) aLsGden|
{ Ev^Xs6 }"
if(sHeader.equals("Content-Length")) ^k_!+8"q{
{ k&~vVx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ey6K@@%
break; [")0{LSA=
} y:,{U*49
} R(zsn;
else wz, \zh
break; 'R'>`?Nh
} PH7L#H^
} M}nalr+#
catch(IOException e){e.printStackTrace ();} 26Yg?:kP
catch(Exception e){e.printStackTrace ();} JQtH},Tr
<5X@r#Lz
WEsH@ [
Utility.log(nFileLength); :EO}uP2
hCDI;'ls
YLCwo]\+>
return nFileLength; a6]!4
} sW]n~kTt'
nuCK7X
\O0fo^+U,,
//保存下载信息（文件指针位置） r[,KE.^6~#
private void write_nPos() @"~\[z5
{ G` 8j ^H,
try{ r]E$uq bR
output = new DataOutputStream(new FileOutputStream(tmpFile)); h)<R#xw
output.writeInt(nStartPos.length); xv*mK1e
for(int i=0;i<nStartPos.length;i++) i]YQq!B
{ }UO,R~q~
// output.writeLong(nPos); gO/(/e>P
output.writeLong(fileSplitterFetch.nStartPos); x$Dv&4
output.writeLong(fileSplitterFetch.nEndPos); <G&v
} _4W#6!
output.close(); srSTQ\l4
} T9$U./69-L
catch(IOException e){e.printStackTrace ();} <VBw1|)$@
catch(Exception e){e.printStackTrace ();} UP`q6]P
} "/"qg
;CvGIp&y
~H$XSNPi
//读取保存的下载信息（文件指针位置） p']AXJ`Z
private void read_nPos() ]S:@=9JB'
{ H|!s.
try{ v]J# SlF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7 dzE"m
int nCount = input.readInt(); \%C[l
nStartPos = new long[nCount]; yjr@v!o
nEndPos = new long[nCount]; m3WV<Cbz
for(int i=0;i<nStartPos.length;i++) w\mF2h
{ P~ykC{nD
nStartPos = input.readLong(); };j&)M
nEndPos = input.readLong(); esHiWHAC
} xL BG}C
input.close(); q)~qd$yMS
} 6+FON$8
catch(IOException e){e.printStackTrace ();} b1#=q0Zl
catch(Exception e){e.printStackTrace ();} t#q>U%!
} J#kdyBmuO
w* I+~o-
c]]F`B
private void processErrorCode(int nErrorCode) '-vyQ^
{ n~ql]Ln
System.err.println("Error Code : " + nErrorCode); [v`4OQF/
} gfYB|VyWo
3/AUV%+
.$k"+E
//停止文件下载 ZFON]$Zk
public void siteStop() IBqY$K+l
{ n1t(ns|
bStop = true; }"-r;i
for(int i=0;i<nStartPos.length;i++) F[u%t34'
fileSplitterFetch.splitterStop(); `#f=&S?k
^55?VQB
Kzb@JBIF
} 9X%Klm 5w
} *I67SBt
//负责部分文件的抓取 Ig<p(G.;}
**FileSplitterFetch.java E8i:ER $$7
*/ p[)<d_
package NetFox; eqR#`
uI2'jEjO
f*],j
import java.io.*; (HI%C@e9
import java.net.*; _Pkh`}W:
9qDGxW '1
Dkb&/k:)
public class FileSplitterFetch extends Thread { bw\=F_>L
(Pd>*G\
zl\#n:|
String sURL; //File URL P1wRt5
long nStartPos; //File Snippet Start Position H1nQ.P]_
long nEndPos; //File Snippet End Position 0vp I#q
int nThreadID; //Thread's ID F4Uk+|]Bu
boolean bDownOver = false; //Downing is over 3\+p1f4
boolean bStop = false; //Stop identical ~N9-an
FileAccessI fileAccessI = null; //File Access interface {9".o,
F29AjW86
}L!`K"^O&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^rwSbM$
{ lc-|Q#$3$
this.sURL = sURL; Xt =bc
this.nStartPos = nStart; E<uOk
this.nEndPos = nEnd; QZr<=}
nThreadID = id; 9C;Y5E~'L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 h*UUtLi%WU
} P;%QA+%7
Hz8`)cv`
(OB8vTRXP
public void run() r6JkoPMh
{ pXv[]v
while(nStartPos < nEndPos && !bStop) %KF:- w
{ h<;[P?z
v{n}%akc
=-LX)|x}
try{ >8fH5
URL url = new URL(sURL); 1omvE9 %zM
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >UY_:cW4%m
httpConnection.setRequestProperty("User-Agent","NetFox"); 9M]"%E!s
String sProperty = "bytes="+nStartPos+"-"; W_\L_)^X
httpConnection.setRequestProperty("RANGE",sProperty); J~3T8e#
Utility.log(sProperty); (Fzh1#
lzG;F]
NCnId}BT
InputStream input = httpConnection.getInputStream(); hxVM]e[
//logResponseHead(httpConnection); WN+Jf
_|3TC1N$n
ACO4u<M)
byte[] b = new byte[1024]; VtiqAh}4
int nRead; IB{ZE/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WV1 Z
{ |HGb.^f?
nStartPos += fileAccessI.write(b,0,nRead); qLi9ym, ]
//if(nThreadID == 1) |7zP8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _F@p53WE
} "jO3Y/>S
@O}j:b
sLdUrD%
Utility.log("Thread " + nThreadID + " is over!"); o?K|[gNi
bDownOver = true; 6bKO;^0
//nPos = fileAccessI.write (b,0,nRead); DhNo +"!z
} Sn2Ds)Pfx3
catch(Exception e){e.printStackTrace ();} qMES<UL>
} gH^$Y~Lx
} xeM':hD.o
IXvz&4VD
|4.o$*0Y
//打印回应的头信息 gkML .u
public void logResponseHead(HttpURLConnection con) ](>7h_2B
{ iWM7,=1+
for(int i=1;;i++) ?lDcaI>+n
{ S~Iw?SK3
String header=con.getHeaderFieldKey(i); ^[}0&_L w
if(header!=null) I"32[?0 (;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $Cd;0gdv
Utility.log(header+" : "+con.getHeaderField(header)); nP\V1pgA
else DJYXC,r
break; QeeC2
} 7Sz'vyiz
} {L4>2rF
t9n
j22#Bw
public void splitterStop() OZ!$%.?l
{ L\Fu']l
bStop = true; >9<8G]vcH
} O%K?l}e
@=NVOJy}c
e*2&s5 #RT
} (Ef2 w['
B_"OA3d_
)n}]]^Sc
/* 4ZJT[zi
**FileAccess.java )yNw2+ ~5
*//文件访问(定位，写) r` `iC5Ii
package NetFox; AqbT{,3yW
import java.io.*; 37O#aJ,K
u1)TG"+0
52MCUl
public class FileAccessI implements Serializable{ _Hd1sx
[pW1=tI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 cl8_rt
RandomAccessFile oSavedFile; -S,ir
long nPos; !/4V^H
Lk`k>Nn)
qXB03}] G
public FileAccessI() throws IOException 2JA&{ch
{ k>:/D
this("",0); W7*_T]
} (I7&8$Zl
JMirz~%ib
s-GleX<
public FileAccessI(String sName,long nPos) throws IOException )&Kn(l)
{ I(^jOgYU
oSavedFile = new RandomAccessFile(sName,"rw"); 7~kpRa@\P
this.nPos = nPos; V#zhGAMy.
oSavedFile.seek(nPos); Nxbd~^j
} f/0v' Jt
piYws<Q
kMl@v`
public synchronized int write(byte[] b,int nStart,int nLen) "#-Nqq
{ R0Ax$Cv{
int n = -1; nE]~E xr
try{ }\`(m\2xo
oSavedFile.write(b,nStart,nLen); 2fkIdy#n@
n = nLen; 7>PF~=
} W(uP`M%][0
catch(IOException e) Z:_m}Ya|
{ y wW-p.
e.printStackTrace (); %aj7-K6:t
} r@*=|0(OrK
' "ZRD_"
&YT_#M
return n; `e'G.@
} Sni&?tcY
a. h?4+^bN
$ZQlIJZ
} T&9`?QD
Cz'xGW{
E$]a?uA:
/* {PN:bb
**SiteInfoBean.java u^`eKak"l
*/ &mh Ln4^
package NetFox; *'Z-OY<V
zc6Ho
tO?21?AD D
public class SiteInfoBean { !2GHJHxv]c
wn &$C0
CnabD{uTf
private String sSiteURL; //Site's URL e{,!|LhpQ
private String sFilePath; //Saved File's Path 0Vf)Rw1%I
private String sFileName; //Saved File's Name _FL<egK
private int nSplitter; //Count of Splited Downloading File LWD.
C=>B_EO
E;9Z\?P
public SiteInfoBean() tY{; U#9
{//nSplitter的缺省值为5 Q2*/`L}m\
//default value of nSplitter is 5 pPoH5CzcK
this("","","",5); |}Q( F+cL
} ows^W8-w
h]qT1(I
>OT\~C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &kb\,mQ
{ mRCHrw?WG
sSiteURL= sURL; F#6cF=};@
sFilePath = sPath; ?p(kh^z
sFileName = sName; /4yOs@#
this.nSplitter = nSpiltter; [d}qG#N
pP3U,n
(/'h4KS@
} p:B ]Ft
F@9Y\. ,
LaDY`u0G%
public String getSSiteURL() 9x(}F<L
{ pL~=Z?(B
return sSiteURL; G[#.mD{k
} 3)y{n%3L
uMHRUi
d4J<,
public void setSSiteURL(String value) L%f;J/
{ 9<v}LeX
sSiteURL = value; E[UO5X
} ~Yl<S(/4
$Buf#8)F*
AQe!Sqg'
public String getSFilePath() [@<G+j
{ Ae6("Oid
return sFilePath; ~6kJ~R4
} %]#VdS|N
l&3ki!
a!D*)z Y
public void setSFilePath(String value) O4E(R?wd
{ *2=W5LaK.
sFilePath = value; n26>>N
} D M}s0O$0
0Z,{s158L
S*g`d;8gV
public String getSFileName() UQ~4c,
{ AFm,CINa
return sFileName; XIRR Al(,
} H*rx{F?
pqeL%="p;
"XhOsMJ
public void setSFileName(String value) *> KHRR<N
{ gQ>2!Qc a-
sFileName = value; <BPRV> 0X
} ]n5"Z,K
q & b5g !
88g47>{X
public int getNSplitter() H|`R4hAk
{ $/paEn"
return nSplitter; b=1%pX_
} [O_^MA,z
&6/%kkv
W' ep6O
public void setNSplitter(int nCount) SX+4HJB
{ q{E"pyt36R
nSplitter = nCount; %b=p< h'(
} qo_]ZKL44
} QrC/ssf}
{6O0.}q]&
C(o.Cy6
/* 9tk" :ld
**Utility.java Pz@/|&]
*/ ]*;F. pZ
package NetFox; 8bOT*^b$H
8a>SC$8"
a4&:@`=
public class Utility { FZXyfZw!|
OJ/SYZ.r
%LQ/q3?_
public Utility() n+;vjVS%
{ P+Z\3re
"- eZZEl(
w!`Umll2
} iYKU[UP?
`*yAiv>
//线程睡眠 g19S
public static void sleep(int nSecond) #3 bv3m
{ %>y;zqZIU
try{ 1b3(
Thread.sleep(nSecond); iF9_b
} 1h=D4yN
catch(Exception e) z(H?VfJo
{ _ 08];M|
e.printStackTrace (); 2a`J%A
} l>&sIX
} .Xd0 Q=1h
8!zbF<W9
//日志 IgM v =^U
public static void log(String sMsg) yC !/PQ"
{ -$YJfQE6G
System.err.println(sMsg); XmWlv{T+
} S|K}k:v8
A#DR9Eq
%0XvJF)s
public static void log(int sMsg) S LGW:
{ ?`AGF%zp
System.err.println(sMsg); ."mlSW"Wm
} ai;\@$ cq
} vM4<d>
.Yx_:h=u
ZL_[4Y
/* 6y Wc1
**TestMethod.java (oaYF+T
*/ {TAw)!R~
package NetFox; \%5MAQS
r]LCvsVa
%8FN0
public class TestMethod { ut&/\k=N
6 h'&6
;7rv
public TestMethod() 6G_<2bO
{ ///xx/weblogic60b2_win.exe u7=T(4a
try{ YaL]>.;Z:"
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); H+l,)Se
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kuKa8c
SiteFileFetch fileFetch = new SiteFileFetch(bean); -BhTkoN)
fileFetch.start(); s@!$='|
} <KQ(c`KW7
catch(Exception e){e.printStackTrace ();} U7H9/<&o
};S0 G!
n%$ &=-Fk
} mX\ ;oV!
T PYDs+U
Q_O*oT(0
public static void main(String[] args) DDw''
{ YBjdp=als
new TestMethod(); QUOKThY?
} tcL2J.
} Zdn!qyR`
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