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)); $C>EnNx
} XNl!(2x'pb
for(int i=0;i<nEndPos.length-1;i++) N;hq
{ @s[bRp`gd
nEndPos = nStartPos[i+1]; *GDU=D}
} V]8fn MH
nEndPos[nEndPos.length-1] = nFileLength; VT9$&\)>O
} ULJI`I|m
} YA|*$$
EHb:(|UA%8
p$=3&qR 6
//启动子线程 FStfGN
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +Q '|->#
for(int i=0;i<nStartPos.length;i++) o4J K$%
{ %DN&K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zz9.OnZ~
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?|L)!LYx
nStartPos,nEndPos,i); .xD-eWw3R
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;F:(5GBi
fileSplitterFetch.start(); y>o#Hq&qM
} 5_O.p3$tV
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), eu4x{NmQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hN}X11
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", &sKYO<6K}
nEndPos = " + nFileLength); '=ZE*nGC
// fileSplitterFetch[nPos.length-1].start(); FD6|>G
x=Ru@nK;
(0][hdI~B
//等待子线程结束 oT_,k}LIX
//int count = 0; OW.ckYt%
//是否结束while循环 "K@os<
boolean breakWhile = false; v ;9s
W,<Vr2J[
v3/cNd3
while(!bStop) QO k%Q$^G
{ 2D!'7ZD
write_nPos(); 5M(?_qj
Utility.sleep(500); FxUH?%w
breakWhile = true; 3Q#VD)
B845BSmh
JrQN-e!
for(int i=0;i<nStartPos.length;i++) s)N1@RBR
{ a0n F U
if(!fileSplitterFetch.bDownOver) sv[)?1S
{ w_-{$8|
breakWhile = false; AV'>
break; <O*q;&9
} !1l2KW<be
} dfrq8n]
if(breakWhile) !!QMcx_C#/
break; EmH{G
ucn aj|
hZFbiGQr\
//count++; !pN,,H6Y
//if(count>4) X3"V1@-i4$
// siteStop(); mA4v 4z
} Sb`>IlT\#
"<&F=gV
PaZFM
System.err.println("文件下载结束！"); a@7we=!
} qmK!d<4
catch(Exception e){e.printStackTrace ();} l5R H~F
} %'>. R
$a-~ozr`C
`KL`^UqR
//获得文件长度 8'?e4;O
public long getFileSize() S)~h|&A(
{ =DtM.oQ>
int nFileLength = -1; xJ3#k;
try{ [$./'-I]
URL url = new URL(siteInfoBean.getSSiteURL()); E`X+fJx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); EfyF]cYL
httpConnection.setRequestProperty("User-Agent","NetFox"); dRu@5 :BP
NLdUe32A
>S~#E,Tg
int responseCode=httpConnection.getResponseCode(); "#9WF}
if(responseCode>=400) WOwIJrP
{ 8Yj(/S3y
processErrorCode(responseCode); <Ei|:m
return -2; //-2 represent access is error We9mkwK7C
} fEpY3od
ja:%j&:
1{,WY(,c
String sHeader; o`#;[
%xg"e O2x
[Ea5Bn;~!
for(int i=1;;i++) 7' 6m;b~F
{ Yd,*LYd2EL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); u'N'<(\k
//Utility.log(in.readLine()); 9 ROKueP
sHeader=httpConnection.getHeaderFieldKey(i); ~MXPiZG?
if(sHeader!=null) H7{ 6t(0j
{ qH-dT,`"{
if(sHeader.equals("Content-Length")) ;hg]5r_
{ jf})"fz-*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); CSD8?k]2
break; "ex? #qD&
} UyJ5}fBJ
} |mKd5[$
else 9]S}m[8k
break; ;~@2YPj
} P8TiB
} Qn<<&i~
catch(IOException e){e.printStackTrace ();} 0h; -Yg
catch(Exception e){e.printStackTrace ();} Ii"cDH9
rbJ-vEzo.#
l&C%oW
Utility.log(nFileLength); O}D]G%,m
_h.[I8xgYG
eLt6Hg)s`9
return nFileLength; hslJs^
} W9u(
#ucOjdquq
SKYS6b
//保存下载信息（文件指针位置） zcA"\
private void write_nPos() B4{A(-Tc
{ ]=pEs6%O3
try{ U%KoG-#
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8gx^e./
output.writeInt(nStartPos.length); `j<'*v zo
for(int i=0;i<nStartPos.length;i++) ?5->F/f&
{ uxR_(~8
// output.writeLong(nPos); e0hT
output.writeLong(fileSplitterFetch.nStartPos); LN7;Yr
output.writeLong(fileSplitterFetch.nEndPos); rL%xl,cn<
} lID5mg31
output.close(); PanyN3rC*
} CUYp(GU
catch(IOException e){e.printStackTrace ();} ."h;H^5
catch(Exception e){e.printStackTrace ();} ;z[yNW8
} mMa7Eyaf
=XYfzR
eDy}_By^
//读取保存的下载信息（文件指针位置） i=SX_#b^
private void read_nPos() -nU_eDy
{ E(S}c*05O
try{ aEgzQono
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H!xBFiOH$n
int nCount = input.readInt(); D}_\oE/n
nStartPos = new long[nCount]; bhg"<I
nEndPos = new long[nCount]; Oo#wPT;1^(
for(int i=0;i<nStartPos.length;i++) #7g~Um%p
{ &'(:xjN
nStartPos = input.readLong(); S4tdWA
nEndPos = input.readLong(); zKI(yC
} ^beW*O!
input.close(); xxedezNko
} tBf u{oC
catch(IOException e){e.printStackTrace ();} CqF< BE
catch(Exception e){e.printStackTrace ();} OCX?U50am
} $y`|zK|G-
7&+Gv6E
20K<}:5t1
private void processErrorCode(int nErrorCode) pM4 j=F
{ 2/h Mx-
System.err.println("Error Code : " + nErrorCode); "cti(0F-d
} TX 12$p\
n ,H;PB
)"q2DjfX*
//停止文件下载 :1AOund
public void siteStop() ^91k@MC
{ L6',s4
bStop = true; z?cRsqf
for(int i=0;i<nStartPos.length;i++) }]f)Fz
fileSplitterFetch.splitterStop(); .&L#%C
0tl
*ZY{^f
} K;YK[M1!
} )~WxNn3rx
//负责部分文件的抓取 8IVKS>
**FileSplitterFetch.java jIEK[vJ`
*/ aeg5ij-]u@
package NetFox; TpnkJygIm
T$k) ^'
=JEnK_@?K\
import java.io.*; 0$P40 7
import java.net.*; 3L#KHTM
RJGf@am&
9m8`4%y=
public class FileSplitterFetch extends Thread { kH{axMNc
8XTVpf4
BV7GzJ2([{
String sURL; //File URL }-Zfljj
long nStartPos; //File Snippet Start Position ;}:"[B3$
long nEndPos; //File Snippet End Position 6KV&E8Gn
int nThreadID; //Thread's ID (?~F}u v
boolean bDownOver = false; //Downing is over cU*7E39
boolean bStop = false; //Stop identical *BSL=8G{
FileAccessI fileAccessI = null; //File Access interface Kr8p:$D};
U}Fk%Jj
bFXCaD!{G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8rNxd=!
{ b4PK
this.sURL = sURL; "n-xsAG
this.nStartPos = nStart; w2V E_
this.nEndPos = nEnd; n_2LkW<?
nThreadID = id; 4rdrl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @V u[Tg}J
} JPzPL\
.8~ x;P6
3Ab$
public void run() J>v>6OC6i
{ 1'B?f# s
while(nStartPos < nEndPos && !bStop) 4"=pcHNV
{ I2Q?7p
Q{kuB+s
Vi-@z;k
try{ |@|D''u>6
URL url = new URL(sURL); 4B pm{b
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6>%NL"* ]
httpConnection.setRequestProperty("User-Agent","NetFox"); .{>-.&
String sProperty = "bytes="+nStartPos+"-"; fE}}>
httpConnection.setRequestProperty("RANGE",sProperty); _RVXE
Utility.log(sProperty); %LmB`DqZ
AkC\CdmA
/n=/WGl
InputStream input = httpConnection.getInputStream(); }]@ "t)"
//logResponseHead(httpConnection); jqmP^ZS
?yh.*,dgi
YJ`>&AJ
byte[] b = new byte[1024]; |Dli6KN
int nRead; LYv2ll`XP
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) h2K
{ l6O(+*6Us
nStartPos += fileAccessI.write(b,0,nRead); #=m5*}=
//if(nThreadID == 1) hNfL /^w
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #+=afJ
} ;pq4El_
v\u+=}rl
Yr@@ty
Utility.log("Thread " + nThreadID + " is over!"); .kV/0!q?
bDownOver = true; g5`YUr+3?h
//nPos = fileAccessI.write (b,0,nRead); WOoVVjMM
} #,C{?0!
catch(Exception e){e.printStackTrace ();} 0KEl+
} fN;y\!q5
} @wz7jzMi
mmti3Y
l-rI|0D#
//打印回应的头信息 |ESe=G
public void logResponseHead(HttpURLConnection con) IYPI5qCR
{ 6zSN?0c
for(int i=1;;i++) .v'8G)6g
{ PeZ=ONY5
String header=con.getHeaderFieldKey(i); >EG;2]M&
if(header!=null) b9Nw98`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); s RB8 jY
Utility.log(header+" : "+con.getHeaderField(header)); _1QNO#X
else >FO=ioNY
break; ygG9ht
} ektFk"W3A\
} IAQ=d4V&
iuRXeiG8
+`xp+Q
public void splitterStop() bK7DGw`1
{ 3dfSu'
bStop = true; +{&g|V
} L[efiiLh$
2*N# %ZUX
'=xl}v
} w1Kyd?~%]
~j_H2+!
dx#N)?
/* $U1'n@/J
**FileAccess.java ^;e`ZtcI
*//文件访问(定位，写) /on p<u
package NetFox; Fwtwf{9I
import java.io.*; ~Km8-b(&
Z2r\aZ-d`
OpfFF;"A'
public class FileAccessI implements Serializable{ (s~hh
snrfHDhUw
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ;6Z?O_zp4
RandomAccessFile oSavedFile; SJfsFi?n
long nPos; -M:.D3,L
-Q/Dbz#-
;1WclQ!(
public FileAccessI() throws IOException gNJ\*]SY
{ $kdfY'u
this("",0); FM5$83Q
} - >2ej4C
se-}d.PwL
6%>0g^`)9Y
public FileAccessI(String sName,long nPos) throws IOException q\\J9`Q$J
{ gDH x+"?
oSavedFile = new RandomAccessFile(sName,"rw"); K4KmoGb
this.nPos = nPos; "+Kr1nW
oSavedFile.seek(nPos); +oc}kv,h]
} Wr;)3K
gS!M7xy
_oWenF
public synchronized int write(byte[] b,int nStart,int nLen) Jx_4:G
{ wI:oe`?H
int n = -1; W'[!4RQL
try{ ;:cM^LJ
oSavedFile.write(b,nStart,nLen); d-4u*>
n = nLen; HO' HkVA
} 3WhJ,~o-y
catch(IOException e) DwI)?a_+
{ 6*%lnd+_
e.printStackTrace (); D:f#
} WH!<Z=#c}
]l4\/EW6
h<uQ~CQg
return n; R!`#pklB
} 9P]TIV.
.Xr_BJ _
{\k9%2V*+
} Mc.KLz&,FC
~"(1~7_
`g#\ Ws
/* E:7vm@+
**SiteInfoBean.java g wk\[I`;
*/ :=* -x
package NetFox; V[%r5!83H
0pu'K)Rb
0-QkRr_I
public class SiteInfoBean { ^b4o 0me
6rk/74gI,a
KxvT}"k
private String sSiteURL; //Site's URL +_+_`q>]
private String sFilePath; //Saved File's Path ym:JtI69
private String sFileName; //Saved File's Name 4;_.|!LN
private int nSplitter; //Count of Splited Downloading File Q)v8hNyUmA
sQR;!-j
]O 2_&cs
public SiteInfoBean() T_r[#j
{//nSplitter的缺省值为5 *rWE.4=&
//default value of nSplitter is 5 lcih [M6z
this("","","",5); /8.;
} ;$nK ^
m^`X|xK-
b*,R9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ros5]5=dP
{ :yv! x
sSiteURL= sURL; JjM^\LwKkL
sFilePath = sPath; ! $n^Ze2 !
sFileName = sName; h~dM*yo;
this.nSplitter = nSpiltter; ]TGJ|X
-i9/1.Z
%e_WO,R
} U9Y'eP.2
u+{5c5_
r,F'Jd5
public String getSSiteURL() (33[N
{ p/@z4TCNX
return sSiteURL; {`-EX
} qlSMg;"Ghw
^y&l!,(A
ZgN*m\l
public void setSSiteURL(String value) `9@!"p f
{ AX6e}-S1n
sSiteURL = value; eK]GyY/Y
} Z$2mVRS`c
)M1.>?b
K":-zS
public String getSFilePath() XfB;^y=u8
{ 2 !{P<
return sFilePath; y#r=^r]l)
} qD2<-E&M/
K?P.1H`
%R(j|a9z
public void setSFilePath(String value) | YvO$4=s
{ Yh"R#
sFilePath = value; S7-?&[oeJ
} Dz.U&+*
Rb#?c+&#
5FzG_ w
public String getSFileName() V$@@!q
{ w W-GBY3
return sFileName; TLi0*)}
} GMksr%0Pj
S# SA:>8s
N+h|Ffnp
public void setSFileName(String value) x%LWcT/
{ .nT"f>S&'
sFileName = value; a]75z)XR
} t,+p!"MRY
NH4EsV]
J\#6U|a""u
public int getNSplitter() l@## Ex9
{ !SVW}Q=5#
return nSplitter; l~!#<=.
} ^fH]Rlx
]kc]YO7i%R
P%.9g
public void setNSplitter(int nCount) V5R``Tp
{ D,]m7yFT
nSplitter = nCount; &AA u:
} MiN68x9
} Ro?yCy:L'
76xgExOU?C
;9d(GP}eE
/* i9w xP i
**Utility.java 7M5HIK6_
*/ T7&itgEYG/
package NetFox; <4^a(Zh
2uV=kqnO
:y0'[LV
public class Utility { iQ~cG[6
DtyT8kr
wMei`svY
public Utility() Dr<%Lr
{ 90M:0SH
CfA F.H
S =eP/
} *9*6n\~aI
WF_G GF{
//线程睡眠 6$2)m;| XY
public static void sleep(int nSecond) p}N'>+@=
{ !j [U
try{ 3KP6M=
Thread.sleep(nSecond); $ 5
} .GLotc
catch(Exception e) {P(IA2J'S
{ zaR~fO
e.printStackTrace (); BwrMRMq"
} C'kd>LAGu
} l{vi{9n)
w~Es,@
//日志 "0nto+v
public static void log(String sMsg) a!4'}gHR
{ hNSV}~h
System.err.println(sMsg); sLb[ZQ;j
} H#G'q_uHH
PJ9JRG7j
^P(HX
public static void log(int sMsg) {H"xC~.
{ Aln\:1MU
System.err.println(sMsg); T3Qa[>+\
} B3e{'14
} %q(n'^#Z.y
LR'F/.Dx
5=5~GX-kr
/* MhHygZT[}
**TestMethod.java xs+MvXTC
*/ :!J!l u
package NetFox; kQwBrb4
EVrOu""
=@&]PYv
public class TestMethod { o=4d2V%m
+*~?JT
3x.|g
public TestMethod() V1;n5YL
{ ///xx/weblogic60b2_win.exe a{,EX[~b
try{ $nBzYRc"3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M*{EK
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]hN%~ ~$>
SiteFileFetch fileFetch = new SiteFileFetch(bean); A1>R8Zuhy
fileFetch.start(); !SKEL6~7
} @R(6w{h9
catch(Exception e){e.printStackTrace ();} zr2%|YF
a*KB'u6&
cPkN)+K
} Z#nj[r!l}
bsR&%C
kT!FC0E{
public static void main(String[] args) bY&s$Ry3"
{ #*1\h=bzmW
new TestMethod(); i{ eDV
} ,z<\Z!+=
} %)u5A!"
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