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)); V/t-
} *?!A
for(int i=0;i<nEndPos.length-1;i++) _))--+cL
{ Z`yW2ON$'
nEndPos = nStartPos[i+1]; *W<|5<<u@
} Za'}26
nEndPos[nEndPos.length-1] = nFileLength; \SA$:^zO
} T;pe7"
} Zrp9`~_g<!
E|ZLz~
%5/h;4
//启动子线程 j12khp?
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Wa'm]J
for(int i=0;i<nStartPos.length;i++) 'cf8VD
{ '+iqbcUd,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .!Os'Y9[,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), G;;iGN
nStartPos,nEndPos,i); 4fau 9bW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |r/4 ({n
fileSplitterFetch.start(); j6&7tK,
} cp5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i]IZ0.?Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); bEl)/z*gy/
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", q6zKyOE
nEndPos = " + nFileLength); CDGN}Q2_
// fileSplitterFetch[nPos.length-1].start(); ?OdJt
"kkZK=}Nv
?Q/9aqHe;
//等待子线程结束 0 hS(9y40
//int count = 0; r&D&xsbQ
//是否结束while循环 Gu\lV c
boolean breakWhile = false; QW6\~l 4
6Ej@;]^^-
z=a{;1A
while(!bStop) 2w67>w\
{ 3QD##Wr^
write_nPos(); e]u3[ao
Utility.sleep(500); QVQ?a&HYS
breakWhile = true; q/^&si
28d=-s=[
aDE)Nf}
for(int i=0;i<nStartPos.length;i++) dS"%( ?o
{ ntEf-x<
if(!fileSplitterFetch.bDownOver) UU2=W
{ }~$96|J
breakWhile = false; NTL`9b
break; ccJ!N
} y3pr(w9A
} 16n8[U!
if(breakWhile) Qh@A7N/L
break; O)9{qU:[b
VH5Vg We
Dv[ 35[Yh
//count++; 3bPF+(`J
//if(count>4) $_NP4V8|z/
// siteStop(); <e7
} [";<YR7iRN
$.-\2;U
1U< g
System.err.println("文件下载结束！"); "+:~#&r
} \hFIg3
catch(Exception e){e.printStackTrace ();} >$p|W~x
} cQldBc
y}!}*Qj+/
BjIKs~CT
//获得文件长度 |HMpVT-;j
public long getFileSize() Z4@GcdZ
{ $r87]y!
int nFileLength = -1; E0a &1j
try{ s6J`i&uu
URL url = new URL(siteInfoBean.getSSiteURL()); 8^%Nl `_2B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); a5# B&|#q
httpConnection.setRequestProperty("User-Agent","NetFox"); '{xPdN
$E]WU?U
Wf>scl`s
int responseCode=httpConnection.getResponseCode(); h$~\to$C
if(responseCode>=400) TEi~X2u
{ ]M5w!O!
processErrorCode(responseCode); `t~Zkb4>
return -2; //-2 represent access is error ',P E25Z
} =g+Rk+jn
#DFfySH)A
OFe?T\dQn
String sHeader; /htM/pR
o7;#B)jWS
jsOid5bs
for(int i=1;;i++) yxz"9PE/P
{ f]Q`8nU
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PhOtSml0
//Utility.log(in.readLine()); y,QJy=?
sHeader=httpConnection.getHeaderFieldKey(i); :gJ?3LwTf
if(sHeader!=null) t\%gP@?
{ /"%(i#<)xs
if(sHeader.equals("Content-Length")) x[5uz))
{ yq2pg8%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); kL1StF#p
break; vMB`TpZ
} Wy`ve~y
} lboi\GP|
else rW(<[2vg
break; V O= o)H\
} YXr"
} ht1d[
catch(IOException e){e.printStackTrace ();} U4*Q;A#
catch(Exception e){e.printStackTrace ();} ^*=.Vuqy
w`$M}oX(
A%$ZB9#zQ
Utility.log(nFileLength); fyE#8h_>4
s35`{PR
swh8-_[c/
return nFileLength; 8A ;)5!
} efu'PfZ`&
n$O[yRMI[
E'O[E=
//保存下载信息（文件指针位置） nF!6
private void write_nPos() bYKe5y=
{ ~!& "b1
try{ }[gk9uM_7
output = new DataOutputStream(new FileOutputStream(tmpFile)); ecRY,MN
output.writeInt(nStartPos.length); Ghb Jty`
for(int i=0;i<nStartPos.length;i++) Z>si%Npm\
{ O<o>/HH$
// output.writeLong(nPos); ~d072qUos
output.writeLong(fileSplitterFetch.nStartPos); BrO" _
output.writeLong(fileSplitterFetch.nEndPos); Dxlpo! ?#
} gx',~
output.close(); p2/Pj)2
} y]e[fZ`L
catch(IOException e){e.printStackTrace ();} R]! [h
catch(Exception e){e.printStackTrace ();} :7P/ZC%
} RU_wr<
9_
/ !@@
//读取保存的下载信息（文件指针位置） Adma~]T9
private void read_nPos() ^L@2%}6b`
{ e: aa
try{ \_w>I_=F
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); XDdF7i}
int nCount = input.readInt(); J )DFH~p
nStartPos = new long[nCount]; 74p=uQ
nEndPos = new long[nCount]; DQy<!Wb+
for(int i=0;i<nStartPos.length;i++) W#.+C6/
{ 4,]z
nStartPos = input.readLong(); ,&5\`
nEndPos = input.readLong(); +338z<'Z!
} 4{rqGC/
input.close(); !F|#TETrt
} Sbp].3^j
catch(IOException e){e.printStackTrace ();} W:gpcR]>
catch(Exception e){e.printStackTrace ();} CVy\']
} nde_%d$
.*Mp+Q}^
~stJO])a
private void processErrorCode(int nErrorCode) <Cbi5DtR
{ NrK.DY4
System.err.println("Error Code : " + nErrorCode); Y*Ra!]62
} nign"r
45aUz@
MoX~ZewWR
//停止文件下载 -+ha4JOB
public void siteStop() \~!!h.xR
{ TF1,7Qd
bStop = true; ]~K&b96(
for(int i=0;i<nStartPos.length;i++) ~EL3I
fileSplitterFetch.splitterStop(); G=ly .
=G,wR'M
k:QeZn(
} <9bfX 91
} l{o,"P"
//负责部分文件的抓取 LpYG!Kl
**FileSplitterFetch.java R9z:K_d,
*/ NZoNsNu*C.
package NetFox; 6D&{+;
/f}!G
je`Ysben
import java.io.*; JJZu%9~[
import java.net.*; >2t.7UhDI
NxW Dw
ki6Lt
public class FileSplitterFetch extends Thread { YEPQ/Pc
zo| '
E#!tXO&,
String sURL; //File URL kfV}ta'^S
long nStartPos; //File Snippet Start Position .<Rw16O
long nEndPos; //File Snippet End Position qeUT]* w
int nThreadID; //Thread's ID QJ,[K_
boolean bDownOver = false; //Downing is over 5(=5GkE)>
boolean bStop = false; //Stop identical 9,wD
FileAccessI fileAccessI = null; //File Access interface 4^Y{ BS fF
e~U]yg5X-
ZQk!Ia7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M '#a.z%
{ TT@U_^o
this.sURL = sURL; _1,hO?TK
this.nStartPos = nStart; +6`+Q2qi
this.nEndPos = nEnd; fg)VO6Wo&
nThreadID = id; PS}'LhZ
fileAccessI = new FileAccessI(sName,nStartPos);//定位 KcvstC`
} l+A)MJd oj
;l %$-/%
?Gl]O3@3
public void run() ~NMx:PP
{ )GYnQoV4
while(nStartPos < nEndPos && !bStop) @tvz9N
{ g&*,j+$ }
awv$ }EFo
`FGYc
try{ s(Bcw`'#
URL url = new URL(sURL); )Yu
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jNvDE}'
httpConnection.setRequestProperty("User-Agent","NetFox"); ZXIw^!8@/
String sProperty = "bytes="+nStartPos+"-"; oo\7\b#Jx
httpConnection.setRequestProperty("RANGE",sProperty); @V&c=8)8
Utility.log(sProperty); g\% Z+Dc
* '_(.Z:
'^.`mT'P
InputStream input = httpConnection.getInputStream(); 9Vru,7g
//logResponseHead(httpConnection); 5%%e$o+
4`B3Kt`o
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byte[] b = new byte[1024]; } J[Z)u
int nRead; 4_`(c1oA
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) UCt}\IJ
{ /go|r '
nStartPos += fileAccessI.write(b,0,nRead); )qRH?Hsb7
//if(nThreadID == 1) Vel}lQD
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %s! |,Cu
} `Gj(>z*
dEZUK vo
q{ [!" ,
Utility.log("Thread " + nThreadID + " is over!"); ]|-sZ<?<i
bDownOver = true; '451H3LC0
//nPos = fileAccessI.write (b,0,nRead); fX.1=BjXi
} k^Q.lb {
catch(Exception e){e.printStackTrace ();} 4*ZY#7h
} .ht-*
} E<jW;trt_
:sQ>oNnz
_U_O0@xi
//打印回应的头信息 !Ii[`H
public void logResponseHead(HttpURLConnection con) hvGD`
{ 31~nay15
for(int i=1;;i++) 9Pb6Z}
{ L#",.x
String header=con.getHeaderFieldKey(i); 35Yf,@VO
if(header!=null) nwp(% fBo
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wFX9F3m
Utility.log(header+" : "+con.getHeaderField(header)); Gl@{y (
else &7i&"TNptP
break; 2t4\L3
} Mf2F LrAh
} E.Q]X]q
|AH>EXhv
:KgH7s}
public void splitterStop() DXo]O}VF
{ jsQHg2Vd
bStop = true; z %Bzf~N9
} @c-
<PVwf`W.
|UlG@Mn
} '4nJ*Xa
D#AqZS>B
b[GhI+_
/* lLp,sNAj
**FileAccess.java :r@t'
*//文件访问(定位，写) `% QvCAR
package NetFox; -72EXO=|
import java.io.*; vQ L$.A3>
PcBD;[cn
fZezDm(Q
public class FileAccessI implements Serializable{ 6Cz O ztn
qVKdc*R-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o K>(yC[
RandomAccessFile oSavedFile; CxTmW5l
long nPos; oNtoqYwH
,sIC=V +
@AF<Xp{
public FileAccessI() throws IOException V^,eW!
{ gfs;?vP
this("",0); zGFD71=#
} i84!x%|P
MoE&)~0u&
(c>g7d<>n
public FileAccessI(String sName,long nPos) throws IOException l2LLM{B
{ p]%di8&;N
oSavedFile = new RandomAccessFile(sName,"rw"); +ID\u <?
this.nPos = nPos; K Ax=C}9
oSavedFile.seek(nPos); vjq2(I)u
} )Xh}N
o]~\u{o#.
d)emTXB(
public synchronized int write(byte[] b,int nStart,int nLen) h7E~I J
{ g"Y_!)X
int n = -1; <(q(5jG
try{ ]'`E
oSavedFile.write(b,nStart,nLen); PR Mg6
n = nLen; &s='$a;4
} UWF \Vx*)b
catch(IOException e) [Q0V5P~Q'
{ v!8=B21
e.printStackTrace (); {u/1ph-
} Y@`uBB[
U fyhd
6,A|9UX=`
return n; F?|Efpzow?
} *m}8L%<HT
X>Vc4n<}
=w!ik9
} ~x^y5[5{
HiA E9
`^Vd*
/* w.-x2Zg},
**SiteInfoBean.java _"ciHYHBQ
*/ cvaG[NF
package NetFox; ;NR|Hi]
A<ds+0
uYMn VE"
public class SiteInfoBean { Xj 1Oxm42
:YI5O/gsk?
_6nAxm&x`%
private String sSiteURL; //Site's URL u<Kowt<ci
private String sFilePath; //Saved File's Path UPI- j#yc
private String sFileName; //Saved File's Name "5&"Ij,/
private int nSplitter; //Count of Splited Downloading File ^o{{kju
/@F'f@;
0+e=s0s.
public SiteInfoBean() <NMJkl-r8r
{//nSplitter的缺省值为5 v-tI`Qpb
//default value of nSplitter is 5 H-PVV&r
this("","","",5); n@8Y6+7i
} 0&UG=q
x ;|HT
TKR#YJQ?K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $<v4c5r]O
{ dS ojq6M
sSiteURL= sURL; 2%sZaM
sFilePath = sPath; UZI:st
sFileName = sName; o]q~sJVk6
this.nSplitter = nSpiltter; u]Ku96!
6sBt6?_T
F:!6B bC
} B/wD~xC?x
HG;;M6
hOwb
public String getSSiteURL() `(FjOd K
{ gsbr8zwG,
return sSiteURL; =&z+7Pe[
} v>]g="5}8
@G"nkB
QN#"c
public void setSSiteURL(String value) :)~l3:O
{ .; F<X\_
sSiteURL = value; lxyTh'
} )8A.Wg4S;c
LDr?'M!D
e*2^
public String getSFilePath() '2.ey33V
{ 0]4X/u#N
return sFilePath; ij$NTY=u
} ubM1Qr
ZaYiby@Ci
g8Ex$,\,
public void setSFilePath(String value) ,Z~`aHhr
{ !T,<p
sFilePath = value; x4I!f)8Q
} tnJ7m8JmC
O2Qmz=%
MJ JC6:
public String getSFileName() SaXt"Ju,AH
{ EHwb?{
return sFileName; klUV&O+=%
} ^ 8}P_
l zFiZx
WqA)V,E
public void setSFileName(String value) K,g6y#1"
{ M{J>yN
sFileName = value; 9<u&27.
} q-(~w!e
ni/s/^
6{I7)@>N
public int getNSplitter() |8'}mjs.Q
{ L<!h3n
return nSplitter; b-_l&;NWg
} AwZ@)0Wy
$mPR)T
nLm'a_
public void setNSplitter(int nCount) ZWCsrV*;
{ a fa\6]m
nSplitter = nCount; *:CTIV5N0
} !igPyhi,hl
} @&m [w'tn
NPH(v`
v@{y}
/* rN&fFI
**Utility.java ^aB;Oo
*/ [)I^v3]U
package NetFox; S%\5"uGa
+ywz@0nx
jr`T6!\
public class Utility { Z;uKnJh
zeMV_rW~
@ym:@<D
public Utility() nk|(cyt)
{ vFe=AY<Rt|
<9]"p2
2E-Kz?,:[
} TgcCR:eL=
1'hpg>U
//线程睡眠 wo&IVy@s$
public static void sleep(int nSecond) 5$U49j
{ 0aY|:
try{ :$G^TD/n
Thread.sleep(nSecond); :rr<#F
} zu}uW,XH-
catch(Exception e) dzIBdth
{ < dE7+w
e.printStackTrace (); ck;:84
} 1O Ft}>1
} ~aotV1"D
#X)DFAtb
//日志 9BakxmAc
public static void log(String sMsg) ,O:4[M!$w
{ W>' DQB
System.err.println(sMsg); XIMh<
} 570ja7C:
1Lf -
iX?j"=!
public static void log(int sMsg) .Yk}iHcW.
{ 4M"'B A<
System.err.println(sMsg); Ue9d0#9
} |}77'w :
} glch06
bD v&;Z
I]HYqI
/* Oyb9 ql^
**TestMethod.java NkUY_rKPb
*/ F42^Uoaz
package NetFox; !IJ YaQ6z
r`ftflNh(
n'ZPB
public class TestMethod { &DQ_qOKD
`V/kM0A5
#IppjaPl8
public TestMethod() 6<z#*`U1
{ ///xx/weblogic60b2_win.exe -qSGa;PJ
try{ HAc"&#pG
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XyB_8(/E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6Lq8#{/]u
SiteFileFetch fileFetch = new SiteFileFetch(bean); -.)f~#8
fileFetch.start(); <e Y2}Ml
} ~I")-2"B
catch(Exception e){e.printStackTrace ();} h/5V~ :)
ZXhNn<
rE"FN~9P
} <DMm [V{
]Y,V)41gCE
1^AQLOiRE1
public static void main(String[] args) +^J&x>5
{ `_DA!
new TestMethod(); \HD:#a
} Uvk:
} |s#,^SJ0
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