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)); ;%wY fq~P
} &nRbI:R
for(int i=0;i<nEndPos.length-1;i++) |([|F|"
{ B5pWSS
nEndPos = nStartPos[i+1]; 8+?|4'\`
} >U.f`24
nEndPos[nEndPos.length-1] = nFileLength; w]%|^:
} U#X6KRZ~g
} G2,9$8qE
HQ7
/}ADV2sF
//启动子线程 A_ftf7,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; FEF $4)ROv
for(int i=0;i<nStartPos.length;i++) m?@0Pf}xa
{ bMrR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^wtr~D|
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), pE~>k:
nStartPos,nEndPos,i); (Cc!Iw'0M
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `1hM3N.nO
fileSplitterFetch.start(); #C`IfP./
} @ uF$m/g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x+%(z8wD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _[kZ:#
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", x=7qC#+)
nEndPos = " + nFileLength); $3BH82
// fileSplitterFetch[nPos.length-1].start(); p bT sn
\nKpJ9!
m,qMRcDF
//等待子线程结束 `yvH0B -
//int count = 0; x,+2k6Wn!
//是否结束while循环 ` &E-
boolean breakWhile = false; F4#^jat{
^p2_p9
1pDL()t
while(!bStop) v!~;QO
{ mjI $z3
write_nPos(); U7(t >/
Utility.sleep(500); HXg#iP^tv
breakWhile = true; VOa7qnh4:[
#K4lnC2qz
>}p'E9J?r
for(int i=0;i<nStartPos.length;i++) 4Gsbcl{
{ 5RUhrE
if(!fileSplitterFetch.bDownOver) 5TB==Fj ?
{ ;LhNz()b
breakWhile = false; Vlka+$4!
break; 4kr! Af
} UD+r{s/%
} f-'$tMs
if(breakWhile) op|:XLR5
break; 03$lgDQ
SBbPO5^](
RPh8n4&("
//count++; p?#%G`dm
//if(count>4) |nu)=Ag
// siteStop(); `;R [*7
} IuW5LS
-IP3I
H+O^el
System.err.println("文件下载结束！"); "AayU
} )2YZ [~3
catch(Exception e){e.printStackTrace ();} \qA^3L~;5
} G#f(oGn :
+'!4kwTR
:VvJx]
//获得文件长度 (e~vrSk+)~
public long getFileSize() o<f#Zi
{ ~Bi{k'A9
int nFileLength = -1; b~L8m4L
try{ ss4<s 5:y
URL url = new URL(siteInfoBean.getSSiteURL()); flr&+=1?D
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qUuvM
httpConnection.setRequestProperty("User-Agent","NetFox"); 1^HUu"Kt
B+pJWl8u
Kd%>:E*
int responseCode=httpConnection.getResponseCode(); D,<#pNO_
if(responseCode>=400) `(dRb
{ OZc.Rtgc
processErrorCode(responseCode); [h=[@jiB
return -2; //-2 represent access is error Q*c |!< &e
} M .J
.o_?n.H'&
eN?:3cP#l
String sHeader; sO;]l"{<
}8\"oA6
=JK# "'
for(int i=1;;i++) 8ba*:sb
{ (+=TKI<=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;xl_9Ht/
//Utility.log(in.readLine()); noLb
sHeader=httpConnection.getHeaderFieldKey(i); !P"=57d}"l
if(sHeader!=null) zm9_[0
{ ` g5S
if(sHeader.equals("Content-Length")) mm@)uV<\
{ zr1,A#BV
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uV'w0`$y
break; <Ky6|&!
} J@4,@+X
} 9>1 $Jv3
else `tjH#W`
break; xSal=a;k
} :87HXz6]jS
} ,2y" \_
catch(IOException e){e.printStackTrace ();} UB7H`)C}
catch(Exception e){e.printStackTrace ();} I$#)k^Q
UN"U#Si)
IY=CTFQ8lm
Utility.log(nFileLength); ~l@-gAyw
jh*aD=y
{+.ai8
return nFileLength; RE?j)$y?`
} 4t<l9Ilp
AWqc?K@
*\5o0~~8J
//保存下载信息（文件指针位置） U}]uPvu
private void write_nPos() ?xgrr7
{ N`Q[OFe
try{ 0 3/<A^
output = new DataOutputStream(new FileOutputStream(tmpFile)); nRL2Z5iO-
output.writeInt(nStartPos.length); W2CQk
for(int i=0;i<nStartPos.length;i++) %!_%%p,f
{ $!-a)U,w$B
// output.writeLong(nPos); _);;@T
output.writeLong(fileSplitterFetch.nStartPos); n;5;D
output.writeLong(fileSplitterFetch.nEndPos); `=B0NC.3
} j& x=?jX
output.close(); ]*Tnu98G}
} =C[2"Y4JK0
catch(IOException e){e.printStackTrace ();} ~LKX2Q:S
catch(Exception e){e.printStackTrace ();} (H*d">`mz
} y,OwO4+y\
_H(:$=$Q
@jp}WwC/
//读取保存的下载信息（文件指针位置） eK]$8l|LI
private void read_nPos() IUJRP
{ lW8!_h"G`n
try{ ]PI|Xl
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); !KEnr`O2u
int nCount = input.readInt(); xqAXfJ.
nStartPos = new long[nCount]; ~1`ZPLVG
nEndPos = new long[nCount]; FlPPz
for(int i=0;i<nStartPos.length;i++) +l,6}tV9
{ ?g5u#Q>!
nStartPos = input.readLong(); ONkHHyT
nEndPos = input.readLong(); M\f1]L|8d
} 4XprVB
input.close(); U'8ub(:&
} \1p_6U7
catch(IOException e){e.printStackTrace ();} =`oQcIkz
catch(Exception e){e.printStackTrace ();} ,PyA$Z
} \EC=#E(
)Fo1[:_B'
h"-}BjL
private void processErrorCode(int nErrorCode) BW61WH?
{ Owa]ax5
System.err.println("Error Code : " + nErrorCode); 3?"JFfYU,'
} NP {O
\~YyY'J
G\S>H
//停止文件下载 {m&8Viq1
public void siteStop() ezOZHY>|#
{ w?+v+k\
bStop = true; %j[DG_
for(int i=0;i<nStartPos.length;i++) LT5rLdn
fileSplitterFetch.splitterStop(); Yom,{;Bv
MDo4{7
hSvA dT]m
} N]k(8K
} ^uy2qO4Yw
//负责部分文件的抓取 qU1^ K
**FileSplitterFetch.java &Vtgh3I
*/ oo:(GfO}
package NetFox; y+C.2 ca
8w[nY.#T
_Q:739&
import java.io.*; ;8G( l
import java.net.*; LD~s@}yH>
--~m{qmy
PUdJ>U
public class FileSplitterFetch extends Thread { NB z3j
P0En&g+~
x*9CK8o=
String sURL; //File URL ZL-YoMHc+_
long nStartPos; //File Snippet Start Position '|\et aD
long nEndPos; //File Snippet End Position R`RLq1WA
int nThreadID; //Thread's ID &y}nd 7o
boolean bDownOver = false; //Downing is over g8_C|lVZi
boolean bStop = false; //Stop identical E[FRx1^R9
FileAccessI fileAccessI = null; //File Access interface f.o,VVYi
as{^~8B
1xJc[q
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \I"UW1)B
{ 5nGDt~a
this.sURL = sURL; ]vPa A
this.nStartPos = nStart; Au6*hv3:
this.nEndPos = nEnd; 4[S0~O{r
nThreadID = id; g36\%L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]J t8]w
} 4<['%7U_[
yvgn}F{}
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public void run() M#sDPT
{ Y{ho[%
while(nStartPos < nEndPos && !bStop) ^Fl6-|^~
{ \qrSJ=}t
R7L:U+*V"
btfjmR<Tp
try{ 8"M*,?.]
URL url = new URL(sURL); K$H>/*&'~
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); `FP)-^A8
httpConnection.setRequestProperty("User-Agent","NetFox"); Qe!Q $
String sProperty = "bytes="+nStartPos+"-"; |vZ\tQ
httpConnection.setRequestProperty("RANGE",sProperty); 7I6bZ;}d
Utility.log(sProperty); :\*<EIk(
,6zH;fi
y=H^U.
InputStream input = httpConnection.getInputStream(); !*0\Yi,6
//logResponseHead(httpConnection); R?Dbv'lp>
~ E)[!y
K8`M~P.
byte[] b = new byte[1024]; LWB"}#vt
int nRead; G36}4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) U#O6l-xe]
{ (;V=A4F-D
nStartPos += fileAccessI.write(b,0,nRead); *ay>MlcV2=
//if(nThreadID == 1) FT1h\K|a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b[^=GF>e
} 8QeM6;^/5
gzK"'4`
)V^J^1
Utility.log("Thread " + nThreadID + " is over!"); .qyk[O
bDownOver = true; wp!<u %
//nPos = fileAccessI.write (b,0,nRead); IX7|_ci
} -$(,&qyk
catch(Exception e){e.printStackTrace ();} ) #/@Jo2F
} |kwkikGQS
} qzVmsxBNP
w$9aTL7
) 0x*>;"o
//打印回应的头信息 No)v&P%
public void logResponseHead(HttpURLConnection con) *-timVlaE
{ 74c1i
for(int i=1;;i++) D!. r$i)
{ Wt&tu2
String header=con.getHeaderFieldKey(i); BX|+"AeF
if(header!=null) "+REv_:
//responseHeaders.put(header,httpConnection.getHeaderField(header)); L%8>deE>;D
Utility.log(header+" : "+con.getHeaderField(header)); p_$03q>oQ
else X517PT8O
break; ^@ GE1
} e&C(IEZ/N;
} v^aARIg
OCzWP,
um@RaU
public void splitterStop() zaX!f~;"
{ A#W%ud4
bStop = true; 71+J{XOC
} K?_4|
}N_9&I
_/"m0/,
} ?-,v0#
k;p:P ?s5Y
H1uNlPT
/* _wWh7'u~G
**FileAccess.java b;&J2:`
*//文件访问(定位，写) <^&NA<2
package NetFox; {m9OgR5U
import java.io.*; &0O1tM*v
5Qp5JMK
`zHtfox!
public class FileAccessI implements Serializable{ eR(PY{
slEsSR'J]
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 uG\+`[-{0
RandomAccessFile oSavedFile; E+$vIYq:W
long nPos; x.r~e)x=
t;9f7~
[R j=k)aBm
public FileAccessI() throws IOException 3LZ0EYVL
{ D"F5-s7
this("",0); jxL5L[
} Ys10r-kDS
\oPW
s> JmLtT
public FileAccessI(String sName,long nPos) throws IOException VdR5ZP
{ CTt3W>'=+
oSavedFile = new RandomAccessFile(sName,"rw"); 9hI4',(rE
this.nPos = nPos; o}p6qB=;1
oSavedFile.seek(nPos); YJ]]6 K+
} 3OV#H%
xW{_c[oA
^;B vd!
public synchronized int write(byte[] b,int nStart,int nLen) 9)sGnD;
{ w%cd$"EH
int n = -1; #;U_ L`q
try{ 5AR\'||u
oSavedFile.write(b,nStart,nLen); 65RWaz;|
n = nLen; MpM-xz~
} "A^9WhUpJ
catch(IOException e) Tn[DF9;?
{ qFmvc
e.printStackTrace (); |jW82L+!N%
} -san%H'
7t\W{y
h\KQ{-Bl
return n; i% k`/X;
} 3|%Q{U
tv)x(MX
v\:>} <gc
} >Vc_.dR)E
:L`
KYVB=14
/* DY?`Y%"
**SiteInfoBean.java ]j0v.[SX
*/ I ms?^`N
package NetFox; bT>% *
8QDRlF:;<
~=P&wBnJ
public class SiteInfoBean { j& f-yc'i-
m2%uGqz
N(Us9
private String sSiteURL; //Site's URL 5xP\6Nx6&5
private String sFilePath; //Saved File's Path M)6_Tal
private String sFileName; //Saved File's Name ,T_HE3K
private int nSplitter; //Count of Splited Downloading File =35^k-VS
VB*$lxX
zl46E~"]x
public SiteInfoBean() y[S5
{//nSplitter的缺省值为5 UDV,co
//default value of nSplitter is 5 nCEt*~t9VE
this("","","",5); FJo N"X
} It!%/Y5
=0`"T!1
]7v-qd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) _h7!
{ +Tde#T&[
sSiteURL= sURL; BBnbXhxZ
sFilePath = sPath; * 4GJ<
sFileName = sName; |h(!CFR
this.nSplitter = nSpiltter; 7Q} P}9n
w``t"v4
yInW?3
} BqK|4-Pf
k}l5v)m
e{.2*>pH
public String getSSiteURL() S1wt>}w0$
{ Nqp%Z7G
return sSiteURL; p0? XR
} =&xamA)
d~uK/R-KD
-ZH]i}$
public void setSSiteURL(String value) U/Z!c\r
{ jE2k\\<a
sSiteURL = value; |HI=ykfI
} {w}PV5<
q .nsGbl
[3;J,P=&
public String getSFilePath() m!a<\0^
{ %FLz}QW*
return sFilePath; W}+Q!T=
} SQWwxFJ
EU TTeFp
[oKc<o7)~"
public void setSFilePath(String value) @~'c(+<3
{ 8Z:NT_Ss
sFilePath = value; ()v[@"J
} {%^q8l4j
KWCA9.w4q
$}2m%$vJO
public String getSFileName() u2y?WcMv
{ S%-L!V ,
return sFileName; 6cVaO@/(
} e(x1w&8dB
c^}gJ
yAG4W[
public void setSFileName(String value) h"Yi'
{ DY^q_+[V
sFileName = value; ypwVzCUG
} A5z`_b4f
K=M5d^K<E
g&O%qX-
public int getNSplitter() 5R?iTB1,
{ ^4x(a&
return nSplitter; *bDuRr?v9
} }:5r#Cd
=B4mi.;@i
Xl;u
public void setNSplitter(int nCount) %A`f>v.7 c
{ f8L
nSplitter = nCount; [{ K$sd
} F=Z|Ji#
} s{x2RDAt
qxG@Zd
m[!t7e
/* 0Q_AF`"
**Utility.java ;:vbOG#aSN
*/ ^O6PZm5J}
package NetFox; Yb]eWLv
*5hg}[n2
!h}x,=`z/
public class Utility { *J=`"^BO
52q@&')D4M
Q9q:HGXxv
public Utility() 3%|LMX]M5_
{ _OZrH(8
' ]l,
~A}"s-Kq5
} 0diQfu)Fi
;XSV}eLu
//线程睡眠 }ARWR.7Cc
public static void sleep(int nSecond) #n]js7
{ uNxR#S
try{ xV}E3Yj2#
Thread.sleep(nSecond); !3v!BJ#+,&
} }?$d~]t)
catch(Exception e) epJVs0W
{ K;,n?Q w
e.printStackTrace (); +IK~a9t
} 8GN0487H
} gnlGL[r|
A/lxXy}D
//日志 *^ \xH,.
public static void log(String sMsg) F +D2 xN@
{ 1mwb&j24n3
System.err.println(sMsg); @E{c P%fv
} ea3AcT6
H\W60|z9
ow:c$Zq
public static void log(int sMsg) 15x~[?!
{ p )etl5
System.err.println(sMsg); `][~0\Y3m
} 6vQAeuz<Fq
} KVvIo1$N
MScjq
D@rOX(m
/* eY"y[
**TestMethod.java `E8m>q Ss
*/ eVjr/nm
package NetFox; 6{8qATLR
q*{i/=~
)Uw QsP
public class TestMethod { :[#HP66[O5
z `T<g!Y
dz5a! e [
public TestMethod() "S(m1L?
{ ///xx/weblogic60b2_win.exe &"BmCDOq
try{ ?=dyU(
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &Y\Vh}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); k`62&"T
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;gcQ9L
fileFetch.start(); ib/B!?/
} MlkTrKdGi
catch(Exception e){e.printStackTrace ();} AA;\7;k{
eG72=l)Mz
"pa5+N&2-
} 6k%N\!_TUW
F[ N{7C3
W @Y$!V<
public static void main(String[] args) \S[:
{ , b ,`;I
new TestMethod(); 1`Cr1pH
} Q!7Er
} "G)-:!H
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