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)); e+j)~RBnu3
} \N4 y<
for(int i=0;i<nEndPos.length-1;i++) gF0q@My~
{ }>'PT-
nEndPos = nStartPos[i+1]; K"0PTWt
} Vm df8[5
nEndPos[nEndPos.length-1] = nFileLength; 9{$<0,?
} rS?pWTg"8
} zt<WXw(
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l%`F&8K
//启动子线程 XO9M_*Va
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S_T1y
for(int i=0;i<nStartPos.length;i++) ]a!xUg!S
{ 1|?05<8
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oXDN+4ge
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )6w}<W*1E
nStartPos,nEndPos,i); fnNYX]_bk
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T`9u!#mT=
fileSplitterFetch.start(); VL/|tL>E^
} mCWhUBghR
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BA:yQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2PeR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E^rbcGJ
nEndPos = " + nFileLength); =Me5ftw
// fileSplitterFetch[nPos.length-1].start(); sj8~?O
Ht-t1q
w~;I7:
//等待子线程结束 eh,~F
//int count = 0; i:cXwQG}B
//是否结束while循环 Pf$pt
boolean breakWhile = false; r 3M1e+'fc
DwV4o^J:l
`zR+tbm
while(!bStop) Kv rX{F=
{ cPl`2&p
write_nPos(); ) gzR=9l
Utility.sleep(500); hxf'5uc
breakWhile = true; 8srBHslI
#!9S}b$
Kv@eI$t5
for(int i=0;i<nStartPos.length;i++) [J C:
{ /c$\X<b);
if(!fileSplitterFetch.bDownOver) r&2~~_d3y
{ D!oc>K$B
breakWhile = false; %&Fk4Z}M
break; Lj"A4i_
} TP}h~8 /;
} R.s^o]vT
if(breakWhile) eVR5Xar
break; v$)q($}p
/Ux*u#
0}:2Q#
//count++; Y(+^;Y3U
//if(count>4) Rm5Kkzd0o
// siteStop(); "iM~Hy
} K9kUS
NB7Y{) w
.,i(2^
System.err.println("文件下载结束！"); *1'`"D~
} jV/CQM5a+
catch(Exception e){e.printStackTrace ();} >;#=gM
} \NGC$p n
8LI-gp\ 2
WA$>pG5s
//获得文件长度 `Rdm-[&
public long getFileSize() CAU0)=M
{ 0vGyI>
int nFileLength = -1; ;oxAe<VIj
try{ ^Q{Bq
URL url = new URL(siteInfoBean.getSSiteURL()); H3H_u4_?SE
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /R LI,.%
httpConnection.setRequestProperty("User-Agent","NetFox"); NJ MJ
X]y)ZF26
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int responseCode=httpConnection.getResponseCode(); <X_!x_x
if(responseCode>=400) !~ZP{IXyo
{ m,R Dr
processErrorCode(responseCode); jDRe)bo4
return -2; //-2 represent access is error nq19Q)
} %Td )0Lqp
vNW jH!'
ZL< MC~
String sHeader; \#rO!z d
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P0i V<T4^
for(int i=1;;i++) phYDs9-K
{ /EMJSr
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1mSaS4!"B
//Utility.log(in.readLine()); O3N_\B:
sHeader=httpConnection.getHeaderFieldKey(i); C*X G_b ]
if(sHeader!=null) 3p*-tBOO
{ gFPi7 o1
if(sHeader.equals("Content-Length")) s-W[.r|
{ ` r']^ ,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AY SSa 1}
break; [Qdq}FYr
} ir:d'g1k
} #Y93y\
else dp5f7>]:(
break; %@R~DBS
} XMRNuEU
} *8ExRQZ$
catch(IOException e){e.printStackTrace ();} `*\{.;,]#
catch(Exception e){e.printStackTrace ();} 3"UsZyN:
ue8qIZH
l12$l<x&M
Utility.log(nFileLength); '+*-s7o{
CkRX>)=py
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return nFileLength; t/Z:)4Z
} p8+/\Ee]B
~"!a9GZ
DP7C?}(
//保存下载信息（文件指针位置） 3P <'F2o
private void write_nPos() [B0K
{ BwJuYH7QJ$
try{ np WEop>
output = new DataOutputStream(new FileOutputStream(tmpFile)); vtMJ@!MN;
output.writeInt(nStartPos.length); cUK\x2
for(int i=0;i<nStartPos.length;i++) bO<0qM~
{ S^cH}-+
// output.writeLong(nPos); }wSy
output.writeLong(fileSplitterFetch.nStartPos); HhkN^S,
output.writeLong(fileSplitterFetch.nEndPos); D6Y6^eS-
} {BO|u{C
output.close(); W3Ulewa
} \h3e-)
catch(IOException e){e.printStackTrace ();} z]Acs
catch(Exception e){e.printStackTrace ();} VG*'"y*%w
} sFb4`
f]d!hz!
Jbp5'e _
//读取保存的下载信息（文件指针位置） E=/[s]@5
private void read_nPos() C;a@Jjor'
{ >Jm"2U}lZW
try{ 4?/7 bc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); u8OxD
int nCount = input.readInt(); aEx(rLd+
nStartPos = new long[nCount]; idJh^YD
nEndPos = new long[nCount]; "]t>ZT:OJ
for(int i=0;i<nStartPos.length;i++) IX?ZbtdX$`
{ S;A)C`X&
nStartPos = input.readLong(); "A]Y~iQ
nEndPos = input.readLong(); =Mhg
} ggou*;'
input.close(); !%mi&ak(Rn
} W>L@j(
catch(IOException e){e.printStackTrace ();} Q-zdJt
catch(Exception e){e.printStackTrace ();} l_v*7d
} 1.SkIu%
H/+{e,SW"
E'%lxr
private void processErrorCode(int nErrorCode) * Zd_ HJi
{ _2jw,WKr
System.err.println("Error Code : " + nErrorCode); z};ZxN
} kb|eQtH
bZ#X9fT
" OGdE_E
//停止文件下载 IMad$AKc
public void siteStop() JJl7JwSTW
{ 2q%K)h
bStop = true; *=vlqpG
for(int i=0;i<nStartPos.length;i++) 3$"/>g/
fileSplitterFetch.splitterStop(); \8"QvC]
7<yp"5><)
abZdGnc
} O3!d(dY=_
} K&UE0JO'
//负责部分文件的抓取 B <+K<,S
**FileSplitterFetch.java s#lto0b"8
*/ tF`MT%{Va
package NetFox; m.V,I}J.q
a{_ KSg
O|UxFnB}
import java.io.*; 8U^D(jrz
import java.net.*; IT1PPm
:l~EE!
Ky&KF0
public class FileSplitterFetch extends Thread { Tiprdvm<
/{DaPqRa
C|6{fd4?
String sURL; //File URL ;i9>}]6
long nStartPos; //File Snippet Start Position >Me]m<$E;
long nEndPos; //File Snippet End Position B~_Spp
int nThreadID; //Thread's ID >Zdi5') 5
boolean bDownOver = false; //Downing is over UE)fUTS
boolean bStop = false; //Stop identical 99KVtgPm
FileAccessI fileAccessI = null; //File Access interface Qcgu`]7}
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6_U|(f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException n{=7 yK
{ 2 `5=0E1k
this.sURL = sURL; n4>cERfa
this.nStartPos = nStart; h]P/KVqR.
this.nEndPos = nEnd; lf8xL9v
nThreadID = id; WW3 B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 cqk]NL`'
} ja75c~RUw
8&T,LNZoY
kr{)
public void run() M;qb7Mu
{ x(vai1CrdH
while(nStartPos < nEndPos && !bStop) tE:X,Lt[
{ l7Y8b`
i>"dBJh]b
v?%3~XoH
try{ .M+v?Ad
URL url = new URL(sURL); &Y=.D:z<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3`rIV*&_{
httpConnection.setRequestProperty("User-Agent","NetFox"); eKJ:?Lxv;
String sProperty = "bytes="+nStartPos+"-"; M,JA;a, _
httpConnection.setRequestProperty("RANGE",sProperty); %|jzEBz@
Utility.log(sProperty); Oc^m_U8>^
8{@`kyy|
IM$0#2\
InputStream input = httpConnection.getInputStream(); j=Q$K#sBt
//logResponseHead(httpConnection); od(:Y(4
aG Ef#A
3d@ef|
byte[] b = new byte[1024]; hA5,w_G/
int nRead; w^U}|h"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) !^1[ s@1
{ d|3o/@k
nStartPos += fileAccessI.write(b,0,nRead); +l.|kkZ?
//if(nThreadID == 1) `#=fA
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v D&Kae<
} lJ'trYaq7
hU)'OKe
7g-$oO
Utility.log("Thread " + nThreadID + " is over!"); lDlj+fK
bDownOver = true; NGSS:
//nPos = fileAccessI.write (b,0,nRead); PnJ*Zea
} mb~./.5F
catch(Exception e){e.printStackTrace ();} ;'hi9L
} Lb^(E-
} jjX%$Hr
s~)L_ p
f^u^-l
//打印回应的头信息 J& )#G@fRX
public void logResponseHead(HttpURLConnection con) Db,= 2e
{ XW^8A77H
for(int i=1;;i++) 0&Qsk!-B
{ \boL`X
String header=con.getHeaderFieldKey(i); $kIo4$.Y$
if(header!=null) &8waih(|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $mD>rx
Utility.log(header+" : "+con.getHeaderField(header)); ret0z|
else bz$Qk;m=H
break; Liij{ahm
} /4^G34
} \.kTe<.:_
9='=-;@/5
IJldN6&\q
public void splitterStop() 2mSD"[%
{ 7:h<`_HT(X
bStop = true; #TIX_RXh
} 2k+=kt
fMyE&#}z
|@+8]dy:l
} 5pB^Y MP
Vj/fAHR`>'
3y/1!A3
/* 9E^~#j@Zr
**FileAccess.java :cEd[Jm9
*//文件访问(定位，写) pK<%<dIc
package NetFox; ,;7`{Nab
import java.io.*; E3LBPXK
=zz+<!!
A"0wvk)UcY
public class FileAccessI implements Serializable{ (eki X*y
>H)^6sJ;%b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {zY`h6d
RandomAccessFile oSavedFile; @T5YsX]qb7
long nPos; sE-x"c
xcw%RUC-
9^(HXH_f
public FileAccessI() throws IOException Y:rJK|m
{ NoJUx['6
this("",0); 9jqO/_7R+
} 6aRGG+H
P$6W`^DZ
2rF?Q?$,B
public FileAccessI(String sName,long nPos) throws IOException 4|FRg
{ NP$e-" 1
oSavedFile = new RandomAccessFile(sName,"rw"); *&(2`#C;
this.nPos = nPos; @X K>
oSavedFile.seek(nPos); N?\bBt@
} nG!&u1*
KlY,NSlQ
#NWZk.S
public synchronized int write(byte[] b,int nStart,int nLen) O>nK,.
{ ZGA)r0] P`
int n = -1; :jBZK=3F>
try{ Q@7l"8#[t
oSavedFile.write(b,nStart,nLen); nt drXg
n = nLen; ,tcP=fdk]
} "3\oQvi.
catch(IOException e) j.<:00<
{ (W7;}gysh
e.printStackTrace (); i5.?g<.H
} eVZa6la"
A<mj8qz
o`b$^hv{A
return n; Hde]DK,d
} bK!,Pc<
W\&WS"=~
}Q!h ov
} Q^*G`&w,
*^X#Eb
umZlIH[7
/* P4hZB_.=
**SiteInfoBean.java fL(':W&n-
*/ 5ze`IY
package NetFox; I/mvQxp
0[V&8\S~'T
(m<R0
public class SiteInfoBean { .=>\Qq%
yJF 2
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private String sSiteURL; //Site's URL `l+ >iM
private String sFilePath; //Saved File's Path $dlnmNP+
private String sFileName; //Saved File's Name {9h`$e=
private int nSplitter; //Count of Splited Downloading File JX2mTQ
I/^q+l.=`{
)w Z49>Y
public SiteInfoBean() Y8D7<V~Md
{//nSplitter的缺省值为5 p.@0=)
//default value of nSplitter is 5 uo]Hi^r.l
this("","","",5); S9$o
} 30A`\+^f
#S@UTJa
)`B -O::
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) -Pqi1pj]
{ {z.[tvE8h
sSiteURL= sURL; f@wsSm
sFilePath = sPath; =@Q#dDnFu%
sFileName = sName; %y~`"l$-
this.nSplitter = nSpiltter; >W>##vK
X*TuQ\T
L{cK^ ,
} ^;0~6uBEJr
H @_eFlT t
4$0jz'
public String getSSiteURL() A Oby*c
{ A8\U CG
return sSiteURL; @`w'
} B.]qrS|
66I|0_
>&$$(Bp
public void setSSiteURL(String value) mgJShn8]
{ B0-4ZT
sSiteURL = value; )p^m}N 6M]
} Aivu%}_|
RnMBGxa
@m+pr\h(
public String getSFilePath() GCcwEl!K^
{ e#l*/G*,
return sFilePath; g0^~J2sDd
} >Sc$R0
mA&RN"+V
F3kC"H
public void setSFilePath(String value) (Wm/$P;
{ d%}crM-KTL
sFilePath = value; r4;5b s6wm
} ^m6k@VM
Gl?P.BCW.&
k)H[XpM
public String getSFileName() v+xgxQGYH
{ ke3HK9P;
return sFileName; - XE79 fQ
} /2g)Z!&+L
%k/ k]:s
iYO wB'z
public void setSFileName(String value) (t]lP/
{ E[)7tr
sFileName = value; Eg@R[ ^T
} =$"zqa.B6
opUKrB
`A4QU,0 8h
public int getNSplitter() Bg+<*z-?e
{ y)?W-5zL
return nSplitter; N&0uXrw
} O ,Pl7x%tK
F<PWBs%
)'BJ4[aq\
public void setNSplitter(int nCount) Ee t+
{ MZUF! B
nSplitter = nCount; pm'@2dT
} QOkE\ro
} Z$OF|ZZQ
E3CiZ4=5
"TBQNWZ
/* iF#}t(CrH
**Utility.java 4 |:Q1
*/ Vu|Br
package NetFox; -V;0_Nx7p
)8 "EI-/.
68&6J's;
public class Utility { Pe+ 8~0o=R
U/1[~429
mV:RmA
public Utility() Q|j@#@O1
{ ,?0-=o
BNL8hK`D
L}e"nzTE6I
} <B]i80.
Dyouk+08x
//线程睡眠 1jUhG2y
public static void sleep(int nSecond) rZ8Y=) e
{ (n":]8}
try{ WuP([8
Thread.sleep(nSecond); wzHjEW
} %468s7Q[Mi
catch(Exception e) #lBpln9
{ t_dw}I
e.printStackTrace (); ?l\gh1{C
} APHtJoS
} ,E*a$cCw
:Fi%Cef|
//日志 v GR \GFm
public static void log(String sMsg) E]u'MX
{ NgE&KPj\
System.err.println(sMsg); !OuTXa,IH
} \pewbu5^
u/!mN2{Rd
;G%wc!
public static void log(int sMsg) 7U{b+=,wK
{ PxP?hk
System.err.println(sMsg); :kp
} :]u}xDv3
} |7S4;
LRCS)UBY(.
z~}StCH(
/* 9U}MXY0
**TestMethod.java a!0?L0_W&
*/ pE(<XD3Q
package NetFox; j?f,~Y<k
O)U$Ef
os(Jr!p_=
public class TestMethod { \[IdR^<YM
ohc/.5Kl
k@t,[
public TestMethod() < o'7{
{ ///xx/weblogic60b2_win.exe 0>~6Z
try{ 1VjeP *
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i"sYf9,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 2W"cTm
SiteFileFetch fileFetch = new SiteFileFetch(bean); uG(~m_7Hx
fileFetch.start(); +4:+qGAJ{
} tRUsZl
catch(Exception e){e.printStackTrace ();} RZV1:hNN
ktw!T{
:|m~<'g
} 7u`}t83a
:S+U}Sm[
&Xl_sDvt
public static void main(String[] args) 3U9+l0mBa
{ [BZ(p
new TestMethod(); vq0M[Vy
} S)'q:`tZo
} /qkIoF2
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