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#(&\g2H
} rDU"l{cg
for(int i=0;i<nEndPos.length-1;i++) }ilX 2s?>
{ :a9$f8*b
nEndPos = nStartPos[i+1]; " qrL:,
} %b`B.A
nEndPos[nEndPos.length-1] = nFileLength; , MU9p*
} aV?r%'~Z
} zGE{Z A
?C9>bKo*2H
}#U3vMx(
//启动子线程 dLTA21b#
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; lpeo^Y}N
for(int i=0;i<nStartPos.length;i++) >.#tNFAs
{ 'P~6_BW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (ZuV5|N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `G.:G/b%H
nStartPos,nEndPos,i); <2RxyoDL6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); AkRZUj\
fileSplitterFetch.start(); _k.gVm
} 60Obek`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _fANl}Mf:
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); eE;")t,
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'k[gxk|d2
nEndPos = " + nFileLength); G6x2!Ny
// fileSplitterFetch[nPos.length-1].start(); sOW,hpNW
>@U lhJtW
4WV)&50
//等待子线程结束 S~ 3|
//int count = 0; )Z2t=&Nw
//是否结束while循环 <0I=XsE1iX
boolean breakWhile = false; oM#S.f?
^7~w yAr
.:#6dG\0z
while(!bStop) YJ^TO\4WM
{ @Ao E>
write_nPos(); jj 9eFB
Utility.sleep(500); "t"&6\
breakWhile = true; >zAI#N4
k|T0Bly3P
QabYkL5@
for(int i=0;i<nStartPos.length;i++) abM4G
{ Y_<(~eN`
if(!fileSplitterFetch.bDownOver) )z?Kq0
{ T3 k#6N.
breakWhile = false; mF !=H%
break; >qI|g={M
} I3V>VLv
} %S<( z5
if(breakWhile) DY%#E9
break; c F(]`49(
}ZWeb#\
o(@F37r{?
//count++; l?%U*~*
//if(count>4) !Rw\k'<GKX
// siteStop(); (&u)FB*
} m=<;)
XL7jUi_4:L
&c!=< <5M
System.err.println("文件下载结束！"); s~6irf/
} L"6@3
catch(Exception e){e.printStackTrace ();} kY6))9 O
} -m~[z
e?D,=A4mV"
D0&{iZ(
//获得文件长度 z[wk-a+w
public long getFileSize() Kv:ih=?
{ Zb7:qe<UN
int nFileLength = -1; aJDu_
try{ RFu]vFff
URL url = new URL(siteInfoBean.getSSiteURL()); c!%:f^7g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'HV}Tr
httpConnection.setRequestProperty("User-Agent","NetFox"); PF(P"f.?D
,uP1U@Cas
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int responseCode=httpConnection.getResponseCode(); 1dK^[;v>3
if(responseCode>=400) /vB%gqJvX
{ gU}?Yy
processErrorCode(responseCode); 7M1*SC
return -2; //-2 represent access is error T<0Bq"'%
} :q4Mnr
"zO+!h'o
i4"xvLK4
String sHeader; FBPT@`~v
a|\_'#
]eq3cwR[|
for(int i=1;;i++) \0pJ+@\T9
{ WiL~b =fT
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 5aTyM_x
//Utility.log(in.readLine()); O,[aL;v
sHeader=httpConnection.getHeaderFieldKey(i); X3Vpxtb
if(sHeader!=null) n.y72-&v
{ y o[!q|z
if(sHeader.equals("Content-Length")) |[TH ~o
{ sh?Dxodp9
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V@K}'f~
break; x9HA^Rj4-
} &w3LMOT
} T+2I:W%
else ~4*9w3t
break; q6{%vd
} p$@=N6)I.k
} GKPqBi[rO
catch(IOException e){e.printStackTrace ();} /kVy#sT|
catch(Exception e){e.printStackTrace ();} 9bXU!l[
}~-)31e'`
\'"q6y
Utility.log(nFileLength); ' n~N*DH
h3xX26l
4#=!VK8ZH
return nFileLength; Xb3vvHdI
} M42D5|tZc
~eL7=G@{
^LT9t2
//保存下载信息（文件指针位置） +.HQ+`8z]
private void write_nPos() m=fmf(
{ W9V%Xc`LQ
try{ AJ:@c7:eS
output = new DataOutputStream(new FileOutputStream(tmpFile)); :"O=/p+*Us
output.writeInt(nStartPos.length); #D+Fq^="P
for(int i=0;i<nStartPos.length;i++) 6M$.gX G.
{ Qq]UEI `Go
// output.writeLong(nPos); j&m<=-q
output.writeLong(fileSplitterFetch.nStartPos); &TWO/F+Y
output.writeLong(fileSplitterFetch.nEndPos); 5 |C;]pq
} n]coqJ
output.close(); 8yFD2(#
} Zml9ndzT
catch(IOException e){e.printStackTrace ();} Ed*`d>
catch(Exception e){e.printStackTrace ();} kC9A
} `Xmpm4 ]
O t`}eL-
T:.J9
//读取保存的下载信息（文件指针位置） n3b@6V1_
private void read_nPos() i$:CGUb
{ x_Ais&Gc
try{ Punbw\9!d,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); PD/JXExK
int nCount = input.readInt(); fBd +gT\S
nStartPos = new long[nCount]; Gh|1%g"gm
nEndPos = new long[nCount]; +S%@/q
for(int i=0;i<nStartPos.length;i++) <)n
{ #^#)OQq]
nStartPos = input.readLong(); |Be.r{l
nEndPos = input.readLong(); s9`T%pg
} NK#Dq&W+&
input.close(); [EGE|
} $X*$,CCIB
catch(IOException e){e.printStackTrace ();} u{p\8v%7
catch(Exception e){e.printStackTrace ();} Bdbw!zRR$
} JBUJc
N{p2@_fnB
<O\z`aA'q
private void processErrorCode(int nErrorCode) FT(EH
{ [V jd)%
System.err.println("Error Code : " + nErrorCode); vlj|[joXw
} 4?yc/F=kI
;-]f4O8
^2^ptQj
//停止文件下载 tfv]AC7x
public void siteStop() B4|%E$1+
{ & bw1
bStop = true; s:]rL&|
for(int i=0;i<nStartPos.length;i++) H#Og0gEE}5
fileSplitterFetch.splitterStop(); V">Uh@[J_
`XWxC:j3%
bh7 1Zu
} & vLX
} 3?5 ~KxOE(
//负责部分文件的抓取 ;:$Na=
**FileSplitterFetch.java o!\O)
*/ ]B,S<*h
package NetFox; b0t];Gc%b
H8-,gV
9I.v?Tap
import java.io.*; .cZ&~ N
import java.net.*; ;_Rx|~!!
1@nR.v"$
x6)
public class FileSplitterFetch extends Thread { RXWjFv~/
e&0B4wVAQ
`chf8
String sURL; //File URL y6PAXvv'{
long nStartPos; //File Snippet Start Position o$-8V:)6d
long nEndPos; //File Snippet End Position v\MH;DW^Z
int nThreadID; //Thread's ID >$Fc=~;Ba
boolean bDownOver = false; //Downing is over mML^kgy\N
boolean bStop = false; //Stop identical U<6k!Y9ny
FileAccessI fileAccessI = null; //File Access interface dl":?D4H
'g=yJ
,-b{oS~u
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException vy"Lsr3
{ ;!~;05^iD
this.sURL = sURL; dIpt&nH&$
this.nStartPos = nStart; 'Vrev8D
this.nEndPos = nEnd; rf`Br\g8
nThreadID = id; nL:vRJr-$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4 ^+hw;
} ASYUKh,h
vSnb>z1
93!a
public void run() X ]a>
{ .y\HQ^j
while(nStartPos < nEndPos && !bStop) _E30t( _.
{ k]>k1Mi=
;Q"F@v}18
(%P* rl
try{ `riv`+J{s
URL url = new URL(sURL); H_AV3 ;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); VG8rd'Z
httpConnection.setRequestProperty("User-Agent","NetFox"); O\D({>
String sProperty = "bytes="+nStartPos+"-"; no/]Me!j=
httpConnection.setRequestProperty("RANGE",sProperty); \iL,l87
Utility.log(sProperty); tm|lqa
5~44R@`
v =?V{"wk!
InputStream input = httpConnection.getInputStream(); FI/YJ@21
//logResponseHead(httpConnection); zhCI+u4/qz
)-QNWN H
@B'Mu:|f
byte[] b = new byte[1024]; W8P**ze4)
int nRead; R Nv<kw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) HJ'93,
{ bNaUzM!,H
nStartPos += fileAccessI.write(b,0,nRead); R_N<j
//if(nThreadID == 1) ?}]kIK}MC
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7O9s5
} f C^l9CRY
pS<b|wu?f
$3[cBX.=
Utility.log("Thread " + nThreadID + " is over!"); NF1D8uI
bDownOver = true; GVfu_z?
//nPos = fileAccessI.write (b,0,nRead); - dOT/%Ux
} L$Leo6<3a
catch(Exception e){e.printStackTrace ();} ]8_h9ziz
} H3c=B /+
} w7Pe<vT
x@Y2jM
,|4Ye
//打印回应的头信息 wU ; f
public void logResponseHead(HttpURLConnection con) 1IlR
{ O\LW 8\M
for(int i=1;;i++) =k*0O_
{ &S3W/lQs
String header=con.getHeaderFieldKey(i); `HS4(2+C
if(header!=null) "~(&5M\8`
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uv-W/p
Utility.log(header+" : "+con.getHeaderField(header)); <?zTnue
else h/fCCfO,
break; kr*c?^b
} QB.'8B_
} {''|iwLr
vaf9b}FL
YT5>pM-%
public void splitterStop() BH-[q9pf
{ 0o<qEo^
bStop = true; \i,cL)HM
} rq1kj 8%2
%)/f; T6
).]m@g:ew
} {\aSEE/'
@|GeR
jSFN/C.9h
/* )T64(_TE
**FileAccess.java da2[
*//文件访问(定位，写) ILi5WuOYX
package NetFox; 0`!Q-G7
import java.io.*; baNfS
E~>6*_?
VRX" @uCD
public class FileAccessI implements Serializable{ bS<@Rd{g
Jrk^J6aa
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 }R1`ThTM
RandomAccessFile oSavedFile; gr 5]5u
long nPos; Qsntf.fT
P*PL6UQ
f^)uK+:.
public FileAccessI() throws IOException +2zuIW.
{ Ib2@Wi
this("",0); KCk?)Qv
} S(J\<)b
mei_aN7zW
RGO:p]t|
public FileAccessI(String sName,long nPos) throws IOException A&P1M6Of
{ U R@BSK'
oSavedFile = new RandomAccessFile(sName,"rw"); r}\h\ {
this.nPos = nPos; Is@a,k
oSavedFile.seek(nPos); +?iM$}8!U
} <s-@!8*(
Uxemlp%%*
5b#6 Y
public synchronized int write(byte[] b,int nStart,int nLen) *|HZ&}
{ j/9QV
int n = -1; KupMndK
try{ CjQ"oQw
oSavedFile.write(b,nStart,nLen); 5FSv"=
n = nLen; , Ln
} u-[t~-(a
catch(IOException e) QWHy=(!
{ ,GX~s5S8
e.printStackTrace (); @E}X-r.^f
} VK'T[5e
b|dCEmFt
O4/n!HOb
return n; ,Us2UEWNv
} >J}n@MZ
c,q"}nE8w
0sd-s~;
} +V9B
^ 6.lb\
*kQCW#y0
/* ~B!O~nvdQ
**SiteInfoBean.java z9 w&uZzi
*/ ~u0xXfv#
package NetFox; A,gx5!J
}{8Fo4/
HB7(
public class SiteInfoBean { -k&{nD|
YvruK:I
V+qJrZ,i
private String sSiteURL; //Site's URL g6g$nY@Jm
private String sFilePath; //Saved File's Path hoR=%pC*
private String sFileName; //Saved File's Name 3l%,D: ?
private int nSplitter; //Count of Splited Downloading File M{xVkXc>
@vQa\|j
GzFE%< 9F
public SiteInfoBean() ,<3uc
{//nSplitter的缺省值为5 _IL2-c8
//default value of nSplitter is 5 u:k:C
this("","","",5); Mjj}E >&
} `x} Dk<HF
3}4p_}f/[4
zq;DIWPIoJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) &G/|lv>j
{ u<]mv
sSiteURL= sURL; XocsSs
sFilePath = sPath; f>r3$WKj
sFileName = sName; rer|k<k;]G
this.nSplitter = nSpiltter; voV:H[RD9
-+}5ma
T;!ukGoFP
} \E@s_fQ]
>{m2E8U0
iS1Gb$?
public String getSSiteURL() *q*HGW5
{ nG"n-$A?<
return sSiteURL; !&`}]qQZ
} f<89$/w
^Cg^`n?@b
e3eVvl5]
public void setSSiteURL(String value) mF'-Is
{ =3|pHc hJ4
sSiteURL = value; &Vt2be*
} &xiOTkqB
;cI#S%uvpn
i-,D_
public String getSFilePath() d=XpO*v,[
{ dC`tN5
return sFilePath; _1sMYhI
} L)F1NuR
'j,oIqx
+2DE/wE]e+
public void setSFilePath(String value) BWUt{,?KU
{ j1YH9T#|D
sFilePath = value; a@#Q:O)4
} ]U,CKJF%/
x_==Ss
)nwZ/&@
public String getSFileName() qL| 5-(P
{ B6bOEPQ
return sFileName; H`m:X,6}
} oYz!O]j;a
tAqA^f*{
~BZXt7DE
public void setSFileName(String value) j z~[5m}J
{ ;8P_av}C
sFileName = value; o]Wz6L
} LJGJ|P
pI7Ssvi^
X9fNGM1
public int getNSplitter() TDlZ!$g(
{ e?V,fzg
return nSplitter; ~G>jw"r
} TbLe6x
vv+D*e&<
*hVb5CS
public void setNSplitter(int nCount) x;]x_fz
{ &%^K,Q"
nSplitter = nCount; 6eQsoKK
} \M5P+Wk'
} Lt1U+o[ot
=<{h^-j;a
#{!O,`qD
/* -(*nSD9
**Utility.java ]cIu|bRO
*/ P##Z[$IJ3
package NetFox; #?9Q{0e
<uZPqi||
!@u&{"{`
public class Utility { Sx8l<X
,"Tjpdf
y%4 Gp
public Utility() P5xI
{ q IM
Z>F@nTzb>
.o}%~g<d
} %[wTz$S"
o{V#f_o
//线程睡眠 bM"fk&
public static void sleep(int nSecond) 2MuO*.9D
{ XaW4C-D&
try{ bGN 54{f
Thread.sleep(nSecond); OX+hZ<y
} 6lsL^]7
catch(Exception e) *>k!hq;j
{ $A`xhh[
e.printStackTrace (); !.EcP=S
} )1f+ld%R
} o/cr{>"N
pI>*u ]x
//日志 R:A'&;S
public static void log(String sMsg) I!0JG`&
{ JSgpb?(
System.err.println(sMsg); =}v ;1m
} h*s`^W3
@EHIp{0.
SK+@HnKd
public static void log(int sMsg) \~>e_;
{ ExCM<$,
System.err.println(sMsg); WL l_'2h
} gg[9u-
} *69c-`o
j0FW8!!-g
R&#tSL
/* 7^MX l
**TestMethod.java d+6]u_J
*/ ;i\C]*
package NetFox; F$Q04Qw
RN[]Jt#6
<Ct_d Cc
public class TestMethod { (#o t^
!v9lk9SV
)TU<:V
public TestMethod() h*Je35
{ ///xx/weblogic60b2_win.exe tPU-1by$
try{ bLbR IY"l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6tn+m54_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); :)IV!_>'d
SiteFileFetch fileFetch = new SiteFileFetch(bean); (a.1M8v+Sg
fileFetch.start(); )eYDQA>J
} ewnfeg1
catch(Exception e){e.printStackTrace ();} rbyY8 bX
"MnSJ2
YT=eVg53
} & Kmy}q
yNa;\UF
ffE#^|
public static void main(String[] args) GK?4@<fY
{ .9h)bf+
new TestMethod(); /0lC KU!=
} S~)w\(r
} x<ax9{
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