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)); &yYK%~}t[
} id*UTY Tg
for(int i=0;i<nEndPos.length-1;i++) ^&.F!
{ 4}l,|7_&I
nEndPos = nStartPos[i+1]; 2O4UytN
} {)`5*sd
nEndPos[nEndPos.length-1] = nFileLength; &hZcjdB
} !iZ*ZPu
} *%g*Np_P
'1bdBx\<.
&&tQ,5H5
//启动子线程 R*QL6t
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9}5Q5OZ
for(int i=0;i<nStartPos.length;i++) vL-%"*>v
{ gBresHrlH
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _hXadLt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8)sqj=
nStartPos,nEndPos,i); *S;v406
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); & 8e~<
fileSplitterFetch.start(); "ua/65cq9
} uD<*g(R
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [=XsI]B\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); TCB<fS~U-
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", & {B,m%G
nEndPos = " + nFileLength); )0/DY
// fileSplitterFetch[nPos.length-1].start(); _a c_8m
Fnr*.k
B<_T"n'#b
//等待子线程结束 4R^'+hy|?
//int count = 0; kigc+R
//是否结束while循环 DGp'Xx_8
boolean breakWhile = false; 7+?
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while(!bStop) d<!bE(
{ O@Xl_QNxc!
write_nPos(); RN!oflb
Utility.sleep(500); .w&{2,a3
breakWhile = true; /eZAAH
cC>.`1:
Km-lWreTH
for(int i=0;i<nStartPos.length;i++) 377$c;4F
{ e}aD<EG
if(!fileSplitterFetch.bDownOver) QK//bV)
{ R0{n0Br
breakWhile = false; Nnx"b 5I}n
break; [NJ!
} +dR$;!WB3
} 8qt|2%
if(breakWhile) %#"uK:(N
break; Pbz-I3+66
]`+>{Sx 1
a*=\-;HaZ
//count++; $JcU0tPq0
//if(count>4) y?Fh%%uNr
// siteStop(); Z\TH=UA
} u5%.T0 P
Jw9|I)H
1jQz%^~
System.err.println("文件下载结束！"); d(R3![:
} K2)),_,@5+
catch(Exception e){e.printStackTrace ();} [|uAfp5R
} u:fiil$
C9({7[k^%
{8b6A~/
//获得文件长度 !t[X/iu
public long getFileSize() 1\_4# @')
{ 4uDz=B+8y
int nFileLength = -1; c1e7h l
try{ U =T[-(:H
URL url = new URL(siteInfoBean.getSSiteURL()); W0l|E&fj[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t5[{ihv~:
httpConnection.setRequestProperty("User-Agent","NetFox"); hm?-QVRPV
>.~^(
Ujb||(W
int responseCode=httpConnection.getResponseCode(); jG8ihi
if(responseCode>=400) 5LXK#+Z
{ C{+~x@
processErrorCode(responseCode); |jc87(x<
return -2; //-2 represent access is error AVHn7olG
} 9%iqequ
L,Uqt,
v;{s@CM m
String sHeader; oZP:}= F
HL*jRl
R6CxNPRJ
for(int i=1;;i++) JF!!)6!2#
{ O:#t> ;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hA)3Ah*
//Utility.log(in.readLine()); LV'v7 2yUH
sHeader=httpConnection.getHeaderFieldKey(i); e6#^4Y/+`
if(sHeader!=null) .2Gn)dZU
{ Nqewtn9n
if(sHeader.equals("Content-Length")) -KbT[]
{ Cv~t~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Ca]vK'(
break; JFl@{6c
} X]Sr]M^EK
} O*!+D-
else Q]7r?nEEhW
break; 6BNOF66kH
} RG#
} 7$;mkHu4H%
catch(IOException e){e.printStackTrace ();} 0;r+E*`DA
catch(Exception e){e.printStackTrace ();} ]r6,^"
x~A""*B~
T?NwSxGo
Utility.log(nFileLength); Y!CZ?c)@
)vhHlZ *+
?OlYJ/!z3
return nFileLength; LYv+Sv
} ^]AjcctGr
u!X[xe;
]%F3 xzOk
//保存下载信息（文件指针位置） 0t6s20*q
private void write_nPos() GP[;+xMBh
{ Kl\A&O*{
try{ ub./U@1
output = new DataOutputStream(new FileOutputStream(tmpFile)); cM.q^{d`
output.writeInt(nStartPos.length); K|E}Ni
for(int i=0;i<nStartPos.length;i++) [Gysx
{ BX2&tQSp
// output.writeLong(nPos); \Qz>us=G
output.writeLong(fileSplitterFetch.nStartPos); Cm(Hu
output.writeLong(fileSplitterFetch.nEndPos); V'\4sPt
} a'XCT@B
output.close(); P[aB}<1f0
} %UY=VE\F
catch(IOException e){e.printStackTrace ();} 5|&Sg}_
catch(Exception e){e.printStackTrace ();} J1P82=$,
} 9akCvY#Q
XR]]g+Z
J4xt!RW!
//读取保存的下载信息（文件指针位置） +TA(crD
private void read_nPos() ,Ix7Yg[
{ %\%1EZQ%
try{ <iv9Mg}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $l-j(=Md
int nCount = input.readInt(); Oa CkU
nStartPos = new long[nCount]; W)$;T%u
nEndPos = new long[nCount]; i#iY;R8
for(int i=0;i<nStartPos.length;i++) !5Z?D8dcx
{ Su6ZO'[)
nStartPos = input.readLong(); :G,GHU'/78
nEndPos = input.readLong(); H[fD >
} u;J9aKD
input.close(); \d]&}`'4{f
} 9F ).i
catch(IOException e){e.printStackTrace ();} wW]|ElYR=
catch(Exception e){e.printStackTrace ();} **dGK_^T0
} Nbuaw[[iz
h9&<-k
0XvMaQXQF
private void processErrorCode(int nErrorCode) a(BWV?A
{ +!'6:F
System.err.println("Error Code : " + nErrorCode); Uw<Lt"ls.
} ZO W{rv]
-GH#nF3G
=KMd! $J\
//停止文件下载 /Y|9!{.
public void siteStop() GcHWalm
{ Uiv;0Tovl
bStop = true; g}L2\i688
for(int i=0;i<nStartPos.length;i++) VOp8 ,!
fileSplitterFetch.splitterStop(); %U-KQI0
!A&Vg #
>2Z:=HT
} pJK puoiX
} NJLU+byU
//负责部分文件的抓取 0ot=BlMu
**FileSplitterFetch.java {;=+#QK/
*/ nLJ]tpw^DH
package NetFox; h:Npi `y
t.485L%
@_h/%>0
import java.io.*; nYTI\f/8v
import java.net.*; 5-5qm[.;
f+-w~cN
YdhrFw0`~r
public class FileSplitterFetch extends Thread { /M\S^!g@
{(7C=)8):
/,c9&it(M
String sURL; //File URL 8!S="_
long nStartPos; //File Snippet Start Position n[AJ'A{
long nEndPos; //File Snippet End Position ZsNUT4
int nThreadID; //Thread's ID Kc}FMu
boolean bDownOver = false; //Downing is over ;'p X1T
boolean bStop = false; //Stop identical 8mV`|2>
FileAccessI fileAccessI = null; //File Access interface >=r094<
aG`G$3_wx
) l0=jb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException j;J4]]R;o
{ X 4;+`
this.sURL = sURL; ]ZHC*r2i
this.nStartPos = nStart; x]Nq|XK
this.nEndPos = nEnd; Gk'J'9*
nThreadID = id; ]C}z3hhk
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :X,1KR
} g>T'R Vb
[[LCEw
xH; 4lw
public void run() MpGWt#
{ c R[DT04
while(nStartPos < nEndPos && !bStop) s:i$s")
{ (B7M*e
f:=q=i
}V6}>!Sb
try{ 9iUkvnphh
URL url = new URL(sURL); qwiM.b5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *:_xy{m\
httpConnection.setRequestProperty("User-Agent","NetFox"); & i)p^AmM
String sProperty = "bytes="+nStartPos+"-"; Cp_"PvTmT
httpConnection.setRequestProperty("RANGE",sProperty); V:2|l!l*
Utility.log(sProperty); q#c\
+f;z{)%B
*-ZJF6
InputStream input = httpConnection.getInputStream(); !H~G_?Mf\O
//logResponseHead(httpConnection); 0waQw7 E
[1G4he%
ZYc)_Og
byte[] b = new byte[1024]; n)^B0DnIk
int nRead; k%VV(P]sT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0 \&4?
{ CQ"5bnR
nStartPos += fileAccessI.write(b,0,nRead); drNfFx2
//if(nThreadID == 1) [gqV}Y"Md
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <eQS16
} !xA;(<K[^
@]gP"Pp
!C&}e8M|eX
Utility.log("Thread " + nThreadID + " is over!"); l2X'4_d
bDownOver = true; ]* ':
//nPos = fileAccessI.write (b,0,nRead); EX|Wd|aK
} U43PHcv_
catch(Exception e){e.printStackTrace ();} lJ:B9n3OzT
} k 32Jz.\B
} $:{uF#
J XbG|L
)zz"DH
//打印回应的头信息 Jd7+~isu~
public void logResponseHead(HttpURLConnection con) ,M5zhp$
{ #92MI#|n9
for(int i=1;;i++) u4rGe!
{ 'HH[[9Q
String header=con.getHeaderFieldKey(i); 305()
if(header!=null) rcY[jF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); [8l8m6
Utility.log(header+" : "+con.getHeaderField(header)); Bd31> %6
else doW_vu
break; 5O]ph[7
} at/besW
} I[c/) N
T%VC$u4F
}3V Q*'X>i
public void splitterStop() _@ev(B
{ nB`pfg
bStop = true; n]r7} 2hM
} roVGS{4T\
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|36d<b Io
} F MHpa
K.JKE"j)d
%f*8JUE16
/* ?qO_t;:0>
**FileAccess.java X8GIRL)lJ
*//文件访问(定位，写) ?FA} ;?v
package NetFox; #JWW ;M6F
import java.io.*; Nw/4z$].J
=NQDxt}
UQ}[2x(Kb
public class FileAccessI implements Serializable{ LeF Z%y)F
Z[[qW f
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4`7N}$j#,
RandomAccessFile oSavedFile; dNUi|IYm$
long nPos; p?>(y
}} J?, >g
bd5\Rt
public FileAccessI() throws IOException pi7W8y
{ :uSo2d
this("",0); AU OL?st
} Wj(O_2
@aAB#,
Tuo`>ZA
public FileAccessI(String sName,long nPos) throws IOException RpOGY{[)[
{ cGIxE[n'
oSavedFile = new RandomAccessFile(sName,"rw"); sC(IeGbX
this.nPos = nPos; K7 -AVMY
oSavedFile.seek(nPos); 64fa0j~<*M
} HQCxO?
g=XvqD<
yT.h[yv"w
public synchronized int write(byte[] b,int nStart,int nLen) wDVKp['
{ bC{}&a
int n = -1; >7V96jL$Y
try{ ^Vso`(Ss
oSavedFile.write(b,nStart,nLen); =8?y$WE
n = nLen; ?\"GT]5D
} 3X=9$xw_
catch(IOException e) %@k@tD6
{ l=GcgxD+"d
e.printStackTrace (); k Pi%RvuQ
} U0 nSI
;wK;
>E;kM B
return n; Tvqq#;I
} U*!q@g_
^a^bsKW
^~9fQJNs
} ;h<(vc3@f
zo6|1xq
z$4g9
/* ,R#pQ 4
**SiteInfoBean.java dWqKt0uh!
*/ `<2k.aW4e8
package NetFox; Q3[MzIk 4
=(2y$,6g?
)S@e&a|
public class SiteInfoBean { [ R
b 5<&hN4g
8eq*q
private String sSiteURL; //Site's URL l25_J.e
private String sFilePath; //Saved File's Path }Z#KPI8\Q
private String sFileName; //Saved File's Name T$rhz)_q
private int nSplitter; //Count of Splited Downloading File xvw@'|
q!iTDg*$
n_QSuh/Wn
public SiteInfoBean() )O\w'|$G
{//nSplitter的缺省值为5 10R#}~D
//default value of nSplitter is 5 .);~H#
this("","","",5); >9dzl#
} 17P5Dr&
|>|f?^
Oy EOb>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P1C{G'cR
{ /S2lA>
sSiteURL= sURL; KCP$i@Pjv
sFilePath = sPath; XuS3#L/3p
sFileName = sName; W>TG!R 5
this.nSplitter = nSpiltter; 0,~||H{
kb3>q($
+q n[F70}
} Cm@rXA/
_|+}4 ap
~&HP}Q$#f
public String getSSiteURL() ^/]w}C#:d
{ M^IEu}
return sSiteURL; ?#s9@R1
} -&q@|h'
cD.afy
!ZNirvk
public void setSSiteURL(String value) J([Y4Em5
{ Y*VF1M,2_
sSiteURL = value; 3bYPi^
} &s6;2G&L$
b'q ru~i
`A\,$(q+
public String getSFilePath() h4p<n&)F
{ '3<T~t
return sFilePath; Z9wKjxu+
} Fi+8|/5
f/xQy}4+~E
i4T=4q
public void setSFilePath(String value) n(RQre
{ `PY=B$?{4
sFilePath = value; FEY_(70
} 7N:3
|7%has3"
Ec/&?|$
public String getSFileName() .*}!XKp0j
{ A1Ru&fd!
return sFileName; sqXwDy+.
} i%@blz:_Y
|$|B0mj
Es<& 6
public void setSFileName(String value) ;*%3J$T+
{ ,J6t 1V
sFileName = value; srlxp_^
} >Nam@,hm
ZLDO&}
"DO|B=EejP
public int getNSplitter() |N5r_V
{ ~=GwNo_
return nSplitter; UuS6y9@v
} dNu?O>=
joz0D!-"#
^F)t>K$0m
public void setNSplitter(int nCount) Mz7qC3Z
{ knn9s0'Q
nSplitter = nCount; Ab #}BHI
} v6U Gr4
} *{:Zdg'~E
5GK> ~2c(
'XJqh|G
/* LZtO Q__B)
**Utility.java E"%dO
*/ |LV}kG(2
package NetFox; *I:a\o~$[
)\KU:_l
~xLo0EV"
public class Utility { "D,}|
&=*sN`
63E)RR_Lh
public Utility() #V{!|Y'
{ 23d*;ri5
redMlHM
Sx:JuK@
} `+h+X9
mxnu\@}(
//线程睡眠 d>gQgQ;g
public static void sleep(int nSecond) r>#4Sr
{ frokl5L@
try{ 2BKiA[ ;;
Thread.sleep(nSecond); kyi"U A82
} +iqzj-e&e[
catch(Exception e) 1B#iJZ}
{ `@xnpA]l
e.printStackTrace (); z6*r<>Bf+b
} ^ Paf-/
} B&QEt[=s
6&+}Hhe
//日志 0.\}D:x(z
public static void log(String sMsg) x)jc
{ )3f<0C>
System.err.println(sMsg); K=! C\T"I%
} :yw8_D3
"!Qi$ ]
b@S~ =
public static void log(int sMsg) 7{tU'`P>
{ W|Cs{rBc?
System.err.println(sMsg); 99\lZ{f(
} ov<vSc<u
} V%(T#_E/6
@Q7^caG
U3jnH
/* xS4?M<|L63
**TestMethod.java 63(XCO
*/ ]z!Df\I
package NetFox; Kv)Kn8df
f?r{Q
b0sj0w/
public class TestMethod { 7g5Pc_
#_Zkke~{
QFK'r\3pU
public TestMethod() p//mVH%
{ ///xx/weblogic60b2_win.exe 4p7j"d5
try{ :IX,mDO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); U2r[.Ru
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); O1@3V/.Wu
SiteFileFetch fileFetch = new SiteFileFetch(bean); "Lyb4#M
fileFetch.start(); #eF,* d
} e(?1`1
catch(Exception e){e.printStackTrace ();} yIf^vx_G
PMi.)%++
# 0d7
} /2''EF';
Ey.%: O-Dv
k]A=Q
public static void main(String[] args) nq,:UYNJ
{ R, #szTu
new TestMethod(); 8`s*+.LI!
} _%3p&1ld
} XqU0AbQ
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