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 S$8F
} mlUj%:Gm#
for(int i=0;i<nEndPos.length-1;i++) G \Nnw==v
{ d @ l
nEndPos = nStartPos[i+1]; p L^3*B.Nr
} `M. I.Z_
nEndPos[nEndPos.length-1] = nFileLength; %<'.c9u5
} 6eA)d#
} FjLMN{eH/
Xr'b{&
jSRi
//启动子线程 UX<)hvKj
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; pf+VYZ#)
for(int i=0;i<nStartPos.length;i++) tkkh<5{C
{ r. (}
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F2ISg'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), z#rp8-HUDS
nStartPos,nEndPos,i); ;>;it5 l=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "Nz@jv?
fileSplitterFetch.start(); (ss,x CF
} *OIBMx#qxn
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZU;jz[}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F6b;qb6n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }qWB=,8HQ
nEndPos = " + nFileLength); Qw }1mRv
// fileSplitterFetch[nPos.length-1].start(); Z",2db
DsD? &:
0IP0zil
//等待子线程结束 s&<76kwl
//int count = 0; Q#.E-\=^
//是否结束while循环 jA[")RVG
boolean breakWhile = false; {,Rlq
JAI.NKB3
25j\p{*
while(!bStop) B@VAXmCaoV
{ 6`bR' 0D
write_nPos(); ]*Q,~uV^|
Utility.sleep(500); u8`S*i/)m
breakWhile = true; ,'9R/7%s
4HX;9HPHE<
UI%4d3
for(int i=0;i<nStartPos.length;i++) K{V.N</
{ 9?~6{!m_9
if(!fileSplitterFetch.bDownOver) rLA-q||
{ a2kAZCQ
breakWhile = false; c&{= aIe w
break; -P&uY`
} [9:";JSl"Y
} uJeJ=7,EO
if(breakWhile) OdL/%Zp}
break; /L@6Ae
+c, ^KHW
T:9M|mD
//count++; bZK^q B
//if(count>4) pjFj{
// siteStop(); @Y>PtA&w*
} 0vBQzM Q
{6wXDZxv
%y*'bS
System.err.println("文件下载结束！"); t)g%9 k^
} -mmQ]'.0
catch(Exception e){e.printStackTrace ();} kC6Y?g
} 64`l?F
|"9vq<`
i~R+g3oi
//获得文件长度 C3~~h|:
public long getFileSize() "a33m:]J
{ YI> xxWA
int nFileLength = -1; HDKY7Yr
try{ Fp[49
URL url = new URL(siteInfoBean.getSSiteURL()); ]gm3|-EiY
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q5@Nd3~h
httpConnection.setRequestProperty("User-Agent","NetFox"); 51H6 W/$
|W@Ko%om
}9#GJ:x`
int responseCode=httpConnection.getResponseCode(); 8bO+[" c
if(responseCode>=400) m}zXy\
{ 0uPcEpIA
processErrorCode(responseCode); +7nvy^m
return -2; //-2 represent access is error pGyk61
} w(t1m]pF[
-yg;,nCg
yOvV"x]
String sHeader; nn$^iw`
EM!S ;i
ITi#p%
for(int i=1;;i++) !|]k2=+I
{ yf`_?gJ6d
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ) LTV+?
//Utility.log(in.readLine()); ko'V8r`V
sHeader=httpConnection.getHeaderFieldKey(i); ^P/OHuDL
if(sHeader!=null) w}t}Sh
{ (x.qyYEoI
if(sHeader.equals("Content-Length")) Fi\)ka\u
{ |ITb1O`_P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); x2aG5@<3
break; -f1}N|hy
} Gl45HyY_
} I,,SR"
else aRI.&3-
break; _5O~]}
} %W|Sl
} :?m"kh ~
catch(IOException e){e.printStackTrace ();} C=U4z|Ym
catch(Exception e){e.printStackTrace ();} A&%7Z^Pp
SkVah:cF-
"{H{-`Ni
Utility.log(nFileLength); 4gdXO
nA.U'=`
4e; le&
return nFileLength; _%B,^0;C
} r<LWiMl?
:eB+t`M
^T1caVb|>
//保存下载信息（文件指针位置） Us2> 5 :\
private void write_nPos() DRXUQH
{ B9cWxe4R#
try{ TlX:05/V8
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]VtP7Y
output.writeInt(nStartPos.length); KbK!4
for(int i=0;i<nStartPos.length;i++) -49I3&
{ tx`^'%GMA
// output.writeLong(nPos); I3T;|;P7
output.writeLong(fileSplitterFetch.nStartPos); DW:\6k
output.writeLong(fileSplitterFetch.nEndPos); ba ,n/yH
} o_kZ
output.close(); _D8 zKp
} ;pfN
catch(IOException e){e.printStackTrace ();} e7&RZ+s#wZ
catch(Exception e){e.printStackTrace ();} H$Pf$D$
} -~4kh]7%
D;+Y0B
w T_l>u
//读取保存的下载信息（文件指针位置） Az#kE.8b*A
private void read_nPos() -;qK_x
{ QyZ'%T5J
try{ XH/!A`ZK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (dO0`wfM
int nCount = input.readInt(); FB>P39u
nStartPos = new long[nCount]; Xa$%`
nEndPos = new long[nCount]; 2_?VR~mA#
for(int i=0;i<nStartPos.length;i++) 6Rq +=X
{ K>XZrt
nStartPos = input.readLong(); O~x{p,s U
nEndPos = input.readLong(); ^(7l!
} HxLuJ
input.close(); ~G6xk/+n-m
} L5 Ai
catch(IOException e){e.printStackTrace ();} s+G(N$0U
catch(Exception e){e.printStackTrace ();} 0%IZ -])
} O(.eHZ=
N#R8ez`
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private void processErrorCode(int nErrorCode) '9<8<d7?
{ +x4*T
System.err.println("Error Code : " + nErrorCode); Z7e"4wA
} JEZ0O&_R
3(.Y>er%U
UalwK
//停止文件下载 Tpkt'|8
public void siteStop() HFz;"s3lWM
{ BuC\Bd^0
bStop = true; %6M%PR~u
for(int i=0;i<nStartPos.length;i++) .O+,1&D5
fileSplitterFetch.splitterStop(); V$u:5"qu0
20J-VN:
;MlPP)*k
} ,&Zk63V
} lx?v .:zl\
//负责部分文件的抓取 Ggv*EsN/cC
**FileSplitterFetch.java O%&N6U
*/ ^R7X!tOq4
package NetFox; v9t'CMU
}ZiJHj'<
yaHkWkl =
import java.io.*; /Vx EqIK
import java.net.*; N7X(gh2h
sY]pszjT
l$W)Vk<B(T
public class FileSplitterFetch extends Thread { "`a,/h'
KyqP@ {
aH,NS
String sURL; //File URL Uqly|FS &n
long nStartPos; //File Snippet Start Position 'S=eW_ 0/
long nEndPos; //File Snippet End Position 'I2[}>mj2
int nThreadID; //Thread's ID N5xI;UV9'
boolean bDownOver = false; //Downing is over OO,%zwgt
boolean bStop = false; //Stop identical oj,;9{-
FileAccessI fileAccessI = null; //File Access interface t0^)Q$
sLK$H|%>m
wDBU+Z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9'ky2 ]w
{ WaE%g
this.sURL = sURL; ;H?tcb*
this.nStartPos = nStart; Ov.oyke4
this.nEndPos = nEnd; J*^ i=y
nThreadID = id; pp >F)A0v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v\}{eP'
} B!)Tytm9u
:"Rx$;a
dw| VH1fS
public void run() 98UI]? 4
{ +NOq>kH@
while(nStartPos < nEndPos && !bStop) 4:kDBV;v
{ 1ZvXRJ)%
%F:; A
g12.4+
try{ fA),^
URL url = new URL(sURL); /\E3p6\*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nD=N MqQ &
httpConnection.setRequestProperty("User-Agent","NetFox"); =%b1EYk
String sProperty = "bytes="+nStartPos+"-"; .j"@7#tW
httpConnection.setRequestProperty("RANGE",sProperty); u|Ng>lU
Utility.log(sProperty); ~cfvL*~5
\GGyz{i
W!* P
InputStream input = httpConnection.getInputStream(); ;9vY5CxzC
//logResponseHead(httpConnection); i3$pqNe
@CC 6`D
Y{X%C\
byte[] b = new byte[1024]; ]BmnE#n&
int nRead; CUaL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $vnx)#r3
{ #"[EVF0%1D
nStartPos += fileAccessI.write(b,0,nRead); P|;f>*^Y
//if(nThreadID == 1) J d,9<m$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); shVEAT'`
} |HwEwL+
7DeBeY
# `@jVX0
Utility.log("Thread " + nThreadID + " is over!"); `?"r\Qo<
bDownOver = true; Lu4>C2{
//nPos = fileAccessI.write (b,0,nRead); $3eoZ1q'U-
} bPuO~#iN~
catch(Exception e){e.printStackTrace ();} c/Li,9cT'
} `SS[[FT$>
} >U]KPL[%
TA~ZN^xI
k#8E9/t@
//打印回应的头信息 GB)< 5I
public void logResponseHead(HttpURLConnection con) w)/~Gn676
{ /9?yw!
for(int i=1;;i++) 0XA0b1VX
{ yFTN/MFt
String header=con.getHeaderFieldKey(i); ]Z*B17//
if(header!=null) <s'0<e!./t
//responseHeaders.put(header,httpConnection.getHeaderField(header)); zV"'-iP
Utility.log(header+" : "+con.getHeaderField(header)); <." @H<-`*
else &@D\4b,?nm
break; z<9Llew^e
} !;Pp)SRzKG
} qga?-oz,<6
cPg{k}9Tvy
CKC5S^Mx
public void splitterStop() bE3mOml
{ 3XNk*Y[5
bStop = true; KD--w(4
} 4"\%/kG
$|AasT5w
{~XnmBs
} pfFHuS~
F;BCSoO4
eAG)+b
/* QI78/gT,d
**FileAccess.java a TPq1u
*//文件访问(定位，写) gq="&
package NetFox; Dd:^ {
import java.io.*; -TS,~`O
D/hq~- g
T>J ,kh
public class FileAccessI implements Serializable{ j}6h}E&dEr
,,lR\!>8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~Bi%8G
RandomAccessFile oSavedFile; >=.3Vydi1
long nPos; %al 5 {
^1_CS*
n+nZ;GJ5d
public FileAccessI() throws IOException mmy/YP)
{ $xjfW/k?M
this("",0); dqO]2d
} 4 =T_h`
E0+~c1P-
vJS}_j]_@
public FileAccessI(String sName,long nPos) throws IOException sd =bw
{ g1(5QWb
oSavedFile = new RandomAccessFile(sName,"rw"); d1'= \PYr
this.nPos = nPos; |I{3~+E h
oSavedFile.seek(nPos); B![:fiR`
} ew]G@66
ngI+afo
"bQi+@
public synchronized int write(byte[] b,int nStart,int nLen) DfVJ~,x~
{ [70 5[
int n = -1; &>QxL d#
try{ }>V=J aG
oSavedFile.write(b,nStart,nLen); O,S>6o)?
n = nLen; $xcZ{C
} ?CcX>R-/
catch(IOException e) M0OIcMTv
{ k4E9=y?
e.printStackTrace (); JAT%s %UC
} @AK&R~<
@]p{%"$
m9+?>/R
return n; sf:IA%.4t
} emB<{kOkw
o2q-x2uB
p(K^Zc
} tmoaa!yRnT
};<?W){!H
ZSyXzop
/* |f!J-H)
**SiteInfoBean.java &0fV;%N
*/ #z7yoP
package NetFox; :{B']~Xf
w0vsdM;G
uZ'Z-!=CL
public class SiteInfoBean { 5(E&jKn&
4jZB%tH
q8FpJ\
private String sSiteURL; //Site's URL Ih4$MG6QC
private String sFilePath; //Saved File's Path P"]l/
private String sFileName; //Saved File's Name gGx(mX._L?
private int nSplitter; //Count of Splited Downloading File {J,4g:4G
t1yOAbI
{<-wm-]mo
public SiteInfoBean() DiTpjk]c`
{//nSplitter的缺省值为5 S\Le;,5Z
//default value of nSplitter is 5 l-S0Gn/'X
this("","","",5); ~*<`PDO?
} 9Oo`4
GlRjbNW?Q
'cQ,;y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >Gk<a
{ po,Ue>n/
sSiteURL= sURL; %[M0TE=J
sFilePath = sPath; Gv}Q/v
sFileName = sName; H)EL0 Kv/
this.nSplitter = nSpiltter; GIn%yB'
{2q0Ko<
8eYEi
} c2fSpvz
@+Sr~:K
|]k,0Y3v
public String getSSiteURL() X.[bgvm~C
{ %lGOExV%
return sSiteURL; P1B=fgT
} dNF_T?E\
a1/+C$ oB
k;2.g$)W[c
public void setSSiteURL(String value) \8s:I+[HH
{ pV;0Hcy
sSiteURL = value; ,S(s
} 5MD'AP:
(E&M[hH+
ZbjUOlE02
public String getSFilePath() ,J-|.ER->
{ '}B"071)<
return sFilePath; 1s(]@gt
} !.q9:|oc
R[S1<m;
yXv@yn
public void setSFilePath(String value) h z{--
{ O8_!!Qd
sFilePath = value; &zJ*afi)
} \=mLL|a
+zq"dj_
U{LS_VI~
public String getSFileName() )*{B_[
{ Sy4|JM-5
return sFileName; #s15AyKz5
} 3 H5
_)!*,\*`{
QjG/H0*mP
public void setSFileName(String value) +PI}$c-|`
{ OVU)t]
sFileName = value; dv3u<XM~
} VBF:MAA
G$&jP:2q
\[.qN
public int getNSplitter() 5|N`:h'9M
{ (xVx|:R[<H
return nSplitter; <eS/-W%n6
} wVnmT94
T]tu#h{ a
w?^[*_Y
public void setNSplitter(int nCount) ;in-)`UC!
{ :yJ([
nSplitter = nCount; ^_DwuY
} Zv=pS (9
} $x]/|u/9
lNyyLLt
CI-za !T
/* L?N-uocT
**Utility.java NCG;`B`i
*/ 92A9gY
package NetFox; W} H~ka
=BE!
2;s[m3
public class Utility { QT^b-~^
\4G9YK-N>
(l-=/6-
public Utility() Zl3e=sg=
{ ~yw]<{?
xP&7i'ag
0H^*VUyW/
} Fb8d=Zc
hhZ%{lqL
//线程睡眠 PsXCpyY!s
public static void sleep(int nSecond) FdzdoMY
{ 'ROz|iJ
try{ ?Z?(ky!
Thread.sleep(nSecond); REK):(i7P
} :DNI\TmhJ
catch(Exception e) 2y;vX|lX]
{ ~&qv[XS
e.printStackTrace (); su1fsoL0
} Dv/7w[F
} h4|}BGO
K[OOI~"C
//日志 M|%bxG^l
public static void log(String sMsg) ckY#oRQ1
{ {j]cL!Od
System.err.println(sMsg); 43M.Hj]
} @P75f5p}<
HB'9&
-aok]w m
public static void log(int sMsg) 6Z J-oT!.
{ 7kE+9HmfMk
System.err.println(sMsg); S\A0gOL^
} xRXvTNEg
} m[3c,Axl7
.<z7$lz\
2(l0Lq*
/* ?#(LH\$l_
**TestMethod.java ]k7%p>c=B
*/ 37a1O>A
package NetFox; 7I"~a<f0X`
5o>`7(t`
rM A%By^L-
public class TestMethod { 6LGl]jHf
!ae?EJm"
,&S0/j
public TestMethod() fK+E5~vQ
{ ///xx/weblogic60b2_win.exe %,02i@Fc
try{ `:V'E>B
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Aixe?A_x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3I~.'>Pd
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9S}rTZkEq
fileFetch.start(); `H$XO{w
} s_fe4K
catch(Exception e){e.printStackTrace ();} @!!u>1
0LL0\ly]
dEKu5GI
} ?yq=c
Um4zI>
uZrp ^
public static void main(String[] args) ^IuhHP
{ a?r$E.W'&
new TestMethod(); r2.w4RMFua
} klFS3G
} sV{\IgH/x
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