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)); _1ax6MwX
} >NJ`*M
for(int i=0;i<nEndPos.length-1;i++) $s<bKju
{ AGMrBd|J{
nEndPos = nStartPos[i+1]; jM[]Uh
} uRnSwJ"hE
nEndPos[nEndPos.length-1] = nFileLength; ?#gYu%7DN
} >A.m`w
} 2)T.Ci cx
+`&-xq76
M32Z3<
//启动子线程 l<-0@(x)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ov|/=bzro
for(int i=0;i<nStartPos.length;i++) WUK{st.z
{ aTFT'(O,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m\eYm;RVj
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~8tb^
nStartPos,nEndPos,i); 3:MAdh[w
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); -p*j9 z
fileSplitterFetch.start(); N VBWF
} d9pZg=$8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tdi^e;:?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n-x%<j(Xf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 7-j=he/
nEndPos = " + nFileLength); Om5+j:YM
// fileSplitterFetch[nPos.length-1].start(); #,;X2%c
#xNXCBl]O
\9%RY]TK3
//等待子线程结束 ICm/9Onh&
//int count = 0; 4h$W4NJK
//是否结束while循环 JXAH/N&i
boolean breakWhile = false; (( {4)5}
XAb-K?)
\[Q*d
while(!bStop) |m>{< :
{ 0u=FlQ }h
write_nPos(); EL:Az~]V
Utility.sleep(500); uoMDf{d
breakWhile = true; 859ID8F
=*=qleC3
Zd<8c^@
for(int i=0;i<nStartPos.length;i++) @f%q ,:
{ @ $2xiE.[
if(!fileSplitterFetch.bDownOver) aP`V
{ q%hxU.h
breakWhile = false; !_pryNcb
break; IiB"F<&[j{
} +^<-;/FZue
} Av,E|C
if(breakWhile) UlH;0P?
break; +&qj`hA-b
o 4cqLMu
ES9|eo6
//count++; &vV_,$
//if(count>4) /2fQM_ ,P
// siteStop(); MB!$s_~o#L
} 5o2|QL
c~v(bK
F8OE
System.err.println("文件下载结束！"); 1zWEK]2.R
} .!yw@kg
catch(Exception e){e.printStackTrace ();} I1fUV72
} e>Q_&6L
b^C2<'
'G8.)eTA'
//获得文件长度 [.LbX`K:
public long getFileSize() B^lm'/,@
{ (C60HbL
int nFileLength = -1; zMbz_22*
try{ U9%#(T$
URL url = new URL(siteInfoBean.getSSiteURL()); ofHe8a8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4t< mX
httpConnection.setRequestProperty("User-Agent","NetFox"); rh$q]
+5oK91o[y
bqSp4TI
int responseCode=httpConnection.getResponseCode(); Fpckb18}(O
if(responseCode>=400) +lED6]+%
{ 6\GL|#G
processErrorCode(responseCode); W>T6Wlxu`6
return -2; //-2 represent access is error *WK0dn
} pipqXe
$|n#L6k
+9[s(E?SY
String sHeader; k/mO(i%qi
\K%A}gnHe
.vk|aIG
for(int i=1;;i++) * vW#XDx
{ V7q-Pfh!y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q}MPl2
//Utility.log(in.readLine()); MrFi0G7u
sHeader=httpConnection.getHeaderFieldKey(i); mrId`<L5l{
if(sHeader!=null) 6ujePi <U
{ #P5tTCM
if(sHeader.equals("Content-Length")) !/wR[`s9w
{ E'wJ+X9 +
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); :y8wv|m
break; TYN~c(
} 3e7P w`gLl
} \&.]!!Q
else 1k?k{Ri
break; iES?}K/q
} iU9>qJ]
} GEQ3r'B|
catch(IOException e){e.printStackTrace ();} $9Asr07
catch(Exception e){e.printStackTrace ();} F2Nb]f
_7Rp.)[&
t182&gpd`
Utility.log(nFileLength); (OT&:WwW
zcE[wM
w;4FN'
return nFileLength; \'.#of
} NZ=`iA8)X
P/;d|M(
y;1l].L
//保存下载信息（文件指针位置） 8e*1L:oB!
private void write_nPos() h4lrt
{ ZA Xw=O5
try{ /R!/)sg
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3 F ke#t
output.writeInt(nStartPos.length); Fg<rz&MR
for(int i=0;i<nStartPos.length;i++) UqEpeLK
{ :qL1jnR^
// output.writeLong(nPos); ;8J+Q0V
output.writeLong(fileSplitterFetch.nStartPos); 60@]^g;$I
output.writeLong(fileSplitterFetch.nEndPos); 1Kc[).O1
} 72;ot`
output.close(); rXG?'jN
} R0_O/o+{
catch(IOException e){e.printStackTrace ();} QGpAG#M9?
catch(Exception e){e.printStackTrace ();} 568qdD`PS
} 2c4x=%
Q{"QpVY8
WZ]f \S
//读取保存的下载信息（文件指针位置） i1k#WgvZR
private void read_nPos() [mJmT->
{ `am]&0g^+(
try{ sfwlv^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #CYDh8X<i
int nCount = input.readInt(); d]<S/D'i
nStartPos = new long[nCount]; LCf)b>C*
nEndPos = new long[nCount]; /swNhDQ"o
for(int i=0;i<nStartPos.length;i++) di5>aAJ)D
{ N6wCCXd
nStartPos = input.readLong(); **!
nEndPos = input.readLong(); Gn7P` t*.
} mpysnKH
input.close(); = gbB)u-Pc
} xQK;3b
catch(IOException e){e.printStackTrace ();} 9/_F
catch(Exception e){e.printStackTrace ();} \n`)>-
} Fy8$'oc
#FQkwX'g
!.}ZlA
private void processErrorCode(int nErrorCode) 4<{]_S6"0y
{ i9Tq h
System.err.println("Error Code : " + nErrorCode); W`2Xn?g
} Y&JK*d
n13#}i{tm
"x P2GZ
//停止文件下载 1*o=I-nOa
public void siteStop() l=.h]]`;
{ j|/4V
bStop = true; a/v!W@Zz}
for(int i=0;i<nStartPos.length;i++) X:1&Pdi
fileSplitterFetch.splitterStop(); }aC@ov]2
j68_3zpl
7\xGMCctM
} cEc_S42Z
} LqA&@
//负责部分文件的抓取 \)'o{l&
**FileSplitterFetch.java +dgHl_,i
*/ W-UMX',0zS
package NetFox; 0/@ ^He8l
zXRq) ;s
-4IHs=`;I
import java.io.*; /suW{8A(E
import java.net.*; eKw!%97>
#lld*I"d
b)1v:X4Bv=
public class FileSplitterFetch extends Thread { F\G-. 1
AZgeu$:7p<
THl={,Rw`
String sURL; //File URL 1q7Y,whp
long nStartPos; //File Snippet Start Position -fm1T|>#
long nEndPos; //File Snippet End Position ~aZy52H_#.
int nThreadID; //Thread's ID ooW;s<6
boolean bDownOver = false; //Downing is over h]{V/
boolean bStop = false; //Stop identical O"6 (k{`
FileAccessI fileAccessI = null; //File Access interface i3[%]_eP.
lNwqWOWy
T1YCld
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException m2|%AD
{ a#L:L8T;j
this.sURL = sURL; pSC\[%K
this.nStartPos = nStart; #FNSE*Y
this.nEndPos = nEnd; o,D7$WzL
nThreadID = id; <jwQ&fm)/R
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "7X[@xX@
} {k"t`uo_
ah9P C7[
uihU)]+@t/
public void run() 7kDqgod^A
{ 1](PuQm7+
while(nStartPos < nEndPos && !bStop) "AcC\iq
{ suF<VJ)&s
](2\w9i%
^_rBEyz@
try{ Nm.G,6<J
URL url = new URL(sURL); yPXa
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c`E0sgp
httpConnection.setRequestProperty("User-Agent","NetFox"); %UXmWXF4$
String sProperty = "bytes="+nStartPos+"-"; C^^AN~ZD
httpConnection.setRequestProperty("RANGE",sProperty); r\."=l
Utility.log(sProperty); }gR!]Cs)^
618k-
#q mv(VB4
InputStream input = httpConnection.getInputStream(); rY,zZR+@
//logResponseHead(httpConnection); |mp~d<&
[0M`uf/u
oH]_2[ !
byte[] b = new byte[1024]; L#6!W
int nRead; ^1mnw@04
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) N}\%r&KR=
{ o0}kRL
nStartPos += fileAccessI.write(b,0,nRead); f]C`]qg
//if(nThreadID == 1) @yj$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ARd*c?Om
} nd#owjB
WM8])}<L
dMlJ2\]u
Utility.log("Thread " + nThreadID + " is over!"); &)ED||r,
bDownOver = true; E gD$A!6N8
//nPos = fileAccessI.write (b,0,nRead); .:I^O[k
} s$D"
catch(Exception e){e.printStackTrace ();} 5>!I6[{
} ^(+@uuBx
} dzRnI*
[fZhfZ)<
lK%)a +2
//打印回应的头信息 %F2T`?t:
public void logResponseHead(HttpURLConnection con) >*]dB|2
{ f>zd,|)At
for(int i=1;;i++) P|tNmv[;
{ 3'zL,WW
String header=con.getHeaderFieldKey(i); nIEIb.-
if(header!=null) f!K{f[aDa
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9cXL4
Utility.log(header+" : "+con.getHeaderField(header)); UpSa7F:Uw
else ~oX`Gih
break; U)6Ew4uRxV
} \ !qe@h<
} $g&_7SJ@
-2qI2Z
B".3NQ
public void splitterStop() 9 K~X+N\
{ &ev#C%Nu
bStop = true; CsX@u#
} @QfbIP9
#9rCF 3P
cyH=LjgJf
} c1M *w9o
ZYLPk<<
AvZOR
/* %zYTTPLZ
**FileAccess.java xFA+ZjBC
*//文件访问(定位，写) 5h[<!f=
package NetFox; R q .2
import java.io.*; ,X)/ T!ff
E^C [G)7n
Im"8+756
public class FileAccessI implements Serializable{ -?L3"rxAP
#:E^($v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 x }.&?m
RandomAccessFile oSavedFile; Ch'e'EmI
long nPos; ]vjMfT%]W
4&<zkAMR
*],=!
public FileAccessI() throws IOException '-V[tyE
{ l9+)h}
this("",0); X&gXhr#dL\
} tpQ8 m(
|[iEi
*t bgIW+h
public FileAccessI(String sName,long nPos) throws IOException 7b*9 Th*a
{ 7e:7RAX
oSavedFile = new RandomAccessFile(sName,"rw"); "Z#MR`;&29
this.nPos = nPos; }_fVv{D
oSavedFile.seek(nPos); 4Ix~Feuph
} S #C;"se
50^CILKo7
A"wso[{
public synchronized int write(byte[] b,int nStart,int nLen) SN5Z@kK
{ *qKf!&
int n = -1; (G 9Ku 8Y
try{ yPks,7U
oSavedFile.write(b,nStart,nLen); 1>)uI@?Rb
n = nLen; ]htx9ds=
} \79aG3MyK
catch(IOException e) &`}ACTY'P
{ (Eo#oX
e.printStackTrace (); D6:"k 2
} ]ZS/9 $
tg;AF<VI
7 aN}lQM
return n; 1Ba.'~:
} w-5_Ru
Qy\Koo
e^h4cC\^
} Q32GI,M%B
D' `[y
DIWcX<s
/* kYu"`_n}
**SiteInfoBean.java mU;\,96#
*/ V/t-
package NetFox; 2l}3L
0c]3 ,#
$Hal]
public class SiteInfoBean { 24I~{Qy
yG:Pg MrB
"FXT8Qxg
private String sSiteURL; //Site's URL '_%`0p1
private String sFilePath; //Saved File's Path =%0r_#F%=
private String sFileName; //Saved File's Name X`0`A2 n
private int nSplitter; //Count of Splited Downloading File Ew2ksZ>B]&
K~ VUD(
o%l|16DR
public SiteInfoBean() ^w~Utx4
{//nSplitter的缺省值为5 ;mXw4_{
//default value of nSplitter is 5 $jN,]N~
this("","","",5); 5uD'Kd$H
} FQw@@
!;.nL-NQ
xmwH~UWp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) IfpFsq:
{ K ZQ `
sSiteURL= sURL; ?OdJt
sFilePath = sPath; 8EAkM*D w
sFileName = sName; ?Q/9aqHe;
this.nSplitter = nSpiltter; 0 hS(9y40
Jc,{n*
so }Kb3n
} pu5-=QN
S@eI3PkE
z=a{;1A
public String getSSiteURL() 2w67>w\
{ 3QD##Wr^
return sSiteURL; $jNp-5+Q;
} n##d!d|g
|d=MX>i|G
APY*SeIV
public void setSSiteURL(String value) j:J{m0
{ bId@V[9
sSiteURL = value; ,XmyC7y<
} S`&YY89{&
4&^BcWqA*f
M;F&Ix
public String getSFilePath() :EZ"D#>y~
{ +)-`$N
return sFilePath; Avi8&@ya
} Wf:I 0
O)9{qU:[b
VH5Vg We
public void setSFilePath(String value) ;c;PNihg
{ A+bU{oLr
sFilePath = value; <e7
} [";<YR7iRN
u7kw/_f
3*$)9'
public String getSFileName() i;8tA!
{ aC=D_JJ\
return sFileName; )]3(ue
} 5<KY}
rg{|/ ;imT
|HMpVT-;j
public void setSFileName(String value) s7}46\/U
{ RNn5,W
sFileName = value; s6J`i&uu
} 8^%Nl `_2B
a5# B&|#q
'{xPdN
public int getNSplitter() $E]WU?U
{ 7iBN!"G0
return nSplitter; p@+r&Mg%W"
} a'2^kds
#Jqa_$\.
o `N /w
public void setNSplitter(int nCount) &o$Pwk\p/
{ cN\Fgbt
nSplitter = nCount; {expx<+4F
} QSq0{
} v\:P_J
m'P,:S)=
{ |[n>k
/* aZ{]t:]
**Utility.java #0;ULZ99aH
*/ k(.6K[b
package NetFox; dCkk5&2n
PhOtSml0
y,QJy=?
public class Utility { 0xQ="aXE
t\%gP@?
/"%(i#<)xs
public Utility() "`4V^1
{ bI"_hvcFp
kL1StF#p
v8!Ts"
} QBI;aG<+b>
,aBo p#
//线程睡眠 >=Pn\"j
public static void sleep(int nSecond) -%eBip,'yl
{ z<c%Xl\$%
try{ .V Cfh+*J#
Thread.sleep(nSecond); ^yo~C3r~
} O>H'ok
catch(Exception e) fyE#8h_>4
{ ^<VJ8jk<
e.printStackTrace (); [|!A3o
} K7CrRT3>6
} IDIok~B=e
M'D l_dx-
//日志 J@vL,C)E6
public static void log(String sMsg) t5Oeb<REz
{ O.% $oV
System.err.println(sMsg); :]hNw1e
} J*} warf&
s}3`%?,6y
m=hUHA,p4
public static void log(int sMsg) <)dHe:
{ ;mAlF>6]\
System.err.println(sMsg); {5, ]7=]
} _^5OoE"}!
} gx',~
j aEUz5
TC+L\7
/* ZcLW8L
**TestMethod.java WQ1~9#
*/ muJR~4
package NetFox; t/57LjV
}pMd/|A,
9cwy;au
public class TestMethod { Z=&cBv4Fs
f6r~Ycf,f
p&nPzZQL(
public TestMethod() ;"K;D@xzh]
{ ///xx/weblogic60b2_win.exe %7y8a`}
try{ zG. \xmp
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vk&6L%_~a
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^I CSs]}1
SiteFileFetch fileFetch = new SiteFileFetch(bean); +'VSD`BR
fileFetch.start(); Ey#7L M)
} !\6<kQg#
catch(Exception e){e.printStackTrace ();} f"}g5eg+
ac%6eW0#
7B)m/%>3s
} 1R+/T
FP_q?=~rFs
qLYz-P'ik
public static void main(String[] args) dz>2/'
{ D,l&^diz
new TestMethod(); QK`5KB(k'
} nR(v~_y[V
} 5Y(<T~
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