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)); FI`][&]V
} J/:9;{R
for(int i=0;i<nEndPos.length-1;i++) Pa'g=-
{ Rs$k3
nEndPos = nStartPos[i+1]; *&Np;^~
} U^-:qT;CX
nEndPos[nEndPos.length-1] = nFileLength; BlF>TI%2
} N2 wBH+3w
} "M3R}<Vt
uosFpa
\25Rq/&w
//启动子线程 vSb$gl5H
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; !iN=py
for(int i=0;i<nStartPos.length;i++) d OQU#5
{ U7bbJ>U_|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m}54yo
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), "7(2m
nStartPos,nEndPos,i); iSCv/Gb:,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }te\) Yk.N
fileSplitterFetch.start(); Uf}s6#
} U3}r.9/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u]lf~EE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Ghs{B8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C!6?.\U/:c
nEndPos = " + nFileLength); P:eY>~m<;
// fileSplitterFetch[nPos.length-1].start(); q"7rd?r52
D(yU:^L
PHU#$LG
//等待子线程结束 O8%+5l`T!
//int count = 0; =;#+8w=^
//是否结束while循环 3xj ?}o
boolean breakWhile = false; JL5 )
C_mPw
a/A$ MXZ_
while(!bStop) v9QR,b`n
{ pTT7#b(t
write_nPos(); 9+k7x,
Utility.sleep(500); Km7HB!=<
breakWhile = true; 1:h{( %`&
se(ZiyHp
+Wrj%}+
for(int i=0;i<nStartPos.length;i++) ~xZFm
{ vPz$jeA
if(!fileSplitterFetch.bDownOver) K;^$n>Y
{ "#anL8
breakWhile = false; q1Gc0{+)
break; \bNN]=
} L 1iA ^x
} R>f$*T
if(breakWhile) 9.:r;HG
break; 1Tz5tU9kR
p_pI=_:
?WyL|;b*
//count++; wQ]!Y?I
//if(count>4) yxP(|
// siteStop(); n]c6nX:'
} wQ-pIi{G
^NwXvp>7-
pB*8D
System.err.println("文件下载结束！"); 2Hl0besm
} I-<U u2
catch(Exception e){e.printStackTrace ();} TJjcX?:(
} xXkP(^ Y
VUAW/
8@y@}
//获得文件长度 ]Y@Db5S$T
public long getFileSize() Z3X/SQ'0
{ y;aZMT.YI
int nFileLength = -1; ^oaFnzJdf
try{ B7HNNX
URL url = new URL(siteInfoBean.getSSiteURL()); H*s_A/$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Zt;3HY=y
httpConnection.setRequestProperty("User-Agent","NetFox"); B'<k*9=Nv8
[\+"<;m$
GIG\bQSv2
int responseCode=httpConnection.getResponseCode(); i8t%v
if(responseCode>=400) mNhVLB
{ .H;[s
processErrorCode(responseCode); 9+><:(,
return -2; //-2 represent access is error r:.3P
} b'F#Y9
D&0y0lxI@
TrA&yXXL
String sHeader; [l"|x75-
otaB$Bb
a^wGc+
for(int i=1;;i++) A9qbE
{ 5A^$!q P
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3jH-!M5
//Utility.log(in.readLine()); )*6]m1
sHeader=httpConnection.getHeaderFieldKey(i); od\-o:bS
if(sHeader!=null) a;@G
{ O.OPIQ=?:w
if(sHeader.equals("Content-Length")) ]rk8Jsg
{ N1dv}!/*.+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B'sgCU
break; R)}ab{A
} b/^i
} oZVq}}R
else _OR@S%$
break; l@:|OGD;8
} (|Zah1k&]
} !Miw.UmPm
catch(IOException e){e.printStackTrace ();} Y'n+,g
catch(Exception e){e.printStackTrace ();} ICq
vq(ElXTO
/XEt2,sI9
Utility.log(nFileLength); qRk<1.
+q*Cw>t /
/O@TqH
return nFileLength; _p<]jt
} z''ITX)oG
$"#2hVO
<<#j?%
//保存下载信息（文件指针位置） ~%.<rc0
private void write_nPos() 04npY+1 8%
{ J9buf}C[
try{ Q:rQ;/b0/
output = new DataOutputStream(new FileOutputStream(tmpFile)); M^C|svm
output.writeInt(nStartPos.length); 4o|-v
for(int i=0;i<nStartPos.length;i++) .lbo\v}2W
{ y+jOk6)W75
// output.writeLong(nPos); i"4&UJu1;
output.writeLong(fileSplitterFetch.nStartPos); CSu}_$wC#
output.writeLong(fileSplitterFetch.nEndPos); Obj?,O
} SLGo/I*
output.close(); mEh([ZnY
} CGYZEPRR
catch(IOException e){e.printStackTrace ();} jEaU;
catch(Exception e){e.printStackTrace ();} /^Ckk
} Jw-?7O
MTyBGrs(
xMOq/")
//读取保存的下载信息（文件指针位置） yDl{18~zv
private void read_nPos() 3n ~n-Jo
{ 3Ql77?&k
try{ aFfd!a"n
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); coG_bX?e
int nCount = input.readInt(); w6cW7}ZD,
nStartPos = new long[nCount]; 0-VC$)S
nEndPos = new long[nCount]; Y:;]qoF
for(int i=0;i<nStartPos.length;i++) ]?1n-w.}r
{ IXA3G7$)
nStartPos = input.readLong(); V$OZC;4
nEndPos = input.readLong(); cUB+fH<B2
} NA`qC.K
input.close(); 3$TU2-x;g
} 0UbY0sYo
catch(IOException e){e.printStackTrace ();} Pjvzefp
catch(Exception e){e.printStackTrace ();} !=/wpsH
} ;kE|Vx
Y<vHL<G
cM|!jnKm
private void processErrorCode(int nErrorCode) OQ=0>;>
{ 8k.<xWDU
System.err.println("Error Code : " + nErrorCode); I=;.o>
} 'c6t,%
f$2DV:wuC
3=@lJ?Ym
//停止文件下载 A ,$CYLj+
public void siteStop() 16cc9%
{ D# Gf.c
bStop = true; }HLs.k4-;
for(int i=0;i<nStartPos.length;i++) O5v)}4
fileSplitterFetch.splitterStop(); ' 5F3,/r
KFuPgp
O3*}L2j@
} vAV{HBQ*
} 9$~a&lXO5
//负责部分文件的抓取 C2a2K={
**FileSplitterFetch.java Fk4T>8q2;
*/ WL#E%6p[
package NetFox; g##yR/L
QT<\E`v
f6$$e+
import java.io.*; 3_ P<0%
import java.net.*; Yvn*evO4
R?Ou=p .
jl)7Jd
public class FileSplitterFetch extends Thread { =^5,ua6
[11D7L%1t
,qz:(Nr
String sURL; //File URL =1SG^rp
long nStartPos; //File Snippet Start Position L\%zNPLS
long nEndPos; //File Snippet End Position wRj||yay#-
int nThreadID; //Thread's ID N"zg)MsX
boolean bDownOver = false; //Downing is over EvJ<X,Bo
boolean bStop = false; //Stop identical ~!iZn
FileAccessI fileAccessI = null; //File Access interface Acl?w }Y
r:~q{
iTu~Y<'m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c|2+J:}p
{ CTP!{<ii
this.sURL = sURL; tbm/gOBw
this.nStartPos = nStart; YLU.]UC
this.nEndPos = nEnd; . l>.
nThreadID = id; :|z.F+-/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 =cwdl7N&I
} ]fdxpqz
25H=RTw
CU+H`-+"J
public void run() tZz *O%
{ %8hx3N8>
while(nStartPos < nEndPos && !bStop) PJn|
{ `D,mZj/b
}Nc Ed;
$ vt6~nfI
try{ Sa 8T'%W
URL url = new URL(sURL); K2@],E?e%|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C(J+tbk
httpConnection.setRequestProperty("User-Agent","NetFox"); Evy_I+l
String sProperty = "bytes="+nStartPos+"-"; b.#0{*/G
httpConnection.setRequestProperty("RANGE",sProperty); "">{8
Utility.log(sProperty); >V$ S\"
/V"6Q'D
$a.,;:
InputStream input = httpConnection.getInputStream(); &^hLFd7j/
//logResponseHead(httpConnection); !M(3[(Ni
{+CBThC
" Z2D@l
byte[] b = new byte[1024]; Gl]z@ZXWIw
int nRead; Bgf'Hm%r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ai$s
{ pm>$'z!.):
nStartPos += fileAccessI.write(b,0,nRead); dml,|k=
//if(nThreadID == 1) u+Sj#iZ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hx$bY
} ~RU-N%Kn
/DGEI&}&:u
DWXHx
Utility.log("Thread " + nThreadID + " is over!"); ^o-)y"GJ
bDownOver = true; ~LU$ no^
//nPos = fileAccessI.write (b,0,nRead); w^=uq3X?
} M=t;t0
catch(Exception e){e.printStackTrace ();} :\cid]y3
} ,1e\}^
} -& T.rsp
bqcwZ6r<
9?Q0O\&uP
//打印回应的头信息 E(miQ
public void logResponseHead(HttpURLConnection con) #8CeTR23cw
{ d]I3zSIC
for(int i=1;;i++) i~i ?M)
{ _(J4
String header=con.getHeaderFieldKey(i); n?S~(4%
if(header!=null) &j!q9F
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Gg# 1k TK
Utility.log(header+" : "+con.getHeaderField(header)); DPBWw[
else a2.@Zyz
break; m_C#fR /I
} z`2Ais@ao
} rGgP9 (
hnTk)nq5#
bS&XlgnKi
public void splitterStop() $l/w.z
{ /kc@ELl
bStop = true; fb_q2p} G
} #p7_\+&5s
BRF4p:
9}<iS w[
} l % 0c{E~
0kxe5*-|
!vGJ7
/* _M)J{ {?:
**FileAccess.java (3 ]!ZV
*//文件访问(定位，写) n,*E s/\
package NetFox; ^2-+MWW.
import java.io.*; LLU]KZhtY|
8<_dNt'91
n<3{QqF
public class FileAccessI implements Serializable{ DP08$Iq
hpOK9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7f]O /
RandomAccessFile oSavedFile; vhz Q.>
long nPos; 0RGqpJxk
CQh6;[\:
|TRl>1rv
public FileAccessI() throws IOException ur JR[$p
{ ~zcB@; :
this("",0); CJf4b:SY@
} jVInTR0f[
ofy)}/i
&]jCoBj+_
public FileAccessI(String sName,long nPos) throws IOException w|( ix;pK
{ .,&6 x.
oSavedFile = new RandomAccessFile(sName,"rw"); IiZXIG4H
this.nPos = nPos; *zl-R*bM$
oSavedFile.seek(nPos); >fx/TSql:J
} 9HG"}CGZP
nV>=n,+s"
0ra+MQBg
public synchronized int write(byte[] b,int nStart,int nLen) I7?s+vyds
{ ^KjxQO6y3
int n = -1; :~LOw}N!aQ
try{ Po7oo9d
oSavedFile.write(b,nStart,nLen); )Kg_E6
n = nLen; m?O"LGBB=
} x%OJ3Qjj=
catch(IOException e) )vy_m_f&
{ sZ%wQqy~k
e.printStackTrace (); {PS|q?
} %+ur41HM
f@H>by N
M6:$ 0(r
return n; CooOBk
} F0tx.]uS
oRQ(l I>
m:5x"o7)ln
} vg-'MG
Dac ,yW
>+F +"NAN
/* 9ve)+Lk
**SiteInfoBean.java b0h>q$b
*/ `V=F>s$W
package NetFox; Oi$$vjs2
C`b)}dY
gM_MK8py
public class SiteInfoBean { :8l#jU`y
]:Sb#=,!&!
mL3 Q
private String sSiteURL; //Site's URL 3Nk )
private String sFilePath; //Saved File's Path ?7Skk
private String sFileName; //Saved File's Name ?Suv.!wfLl
private int nSplitter; //Count of Splited Downloading File E#/vgm=W;
I^!c1S
xG|n7w*
public SiteInfoBean() 7-2,|(Xg
{//nSplitter的缺省值为5 <-N7Skkk!
//default value of nSplitter is 5 &D#B"XI
this("","","",5); yYPFk
} g{^(EZ,
*(j-jbA
"J*LR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7YQ689"J6B
{ b_GAK
sSiteURL= sURL; '[Z.\
sFilePath = sPath; b*dEX%H8sf
sFileName = sName; Lo uYY:Q
this.nSplitter = nSpiltter; Qvm[2mb
&C.m*^`^
?oulQR6:
} M<cm]
w_9[y
% QI6`@Y"
public String getSSiteURL() lCK|PY*
{ "<1-9CMl
return sSiteURL; Vo(V<2lw}
} _NB8>v
28=L9q
$[g8j`or!
public void setSSiteURL(String value) <:I]0|[
{ EV|L~^Q
sSiteURL = value; c%x.cbu>
} y3!#*NU
mFJb9,
:B1a2Y^"
public String getSFilePath() 7oFA5T _
{ &~sk7iGi
return sFilePath; -r@/8"
} ;BjJ<?^{
Ops""#Zi
@W\H%VR
public void setSFilePath(String value) &T[BS;
{ $Y<(~E$FX
sFilePath = value; D[bPm:\0M
} iYb{qv_4
avEsX_.
!)h?2#V8;
public String getSFileName() "MU)8$d
{ .8/W_iC92
return sFileName; /<it2=
} Zm#qW2a]P
Y"'k $jS-
%a$Fsn
public void setSFileName(String value) 'QxPQcU
{ 5HMDug;
sFileName = value; jW0aIS2O
} Nj|~3 *KO
z+F:_
O:Ob{k
public int getNSplitter() w"?E=RS
{ l527>7 eT
return nSplitter; iYl$25k/1
} @d_;p<\l
V9<CeTl'
(]*!`(_b
public void setNSplitter(int nCount) 2Wq/_:
{ 4&'_~qU
nSplitter = nCount; k ks ?S',
} }*R.>jQ+Y
} 6jo+i[h
u(P;) E"1
<nE|Y@S
/* <n|.Z-gF\
**Utility.java Q5pm^X._j
*/ jN^09T49
package NetFox; ,Z p9,nf
:R9 DJh\
/7-qb^V
public class Utility { AlQ
:h)A/k_
@AAkEWo)_
public Utility() 1PdxoRa4=
{ o;M-M(EZQ6
f+Da W
8et.A
} }t9A#GOz
9G=ZB^
//线程睡眠 ky98Bz%
public static void sleep(int nSecond) {;j@-=pV
{ _=68iDXm
try{ >Gyg`L\
Thread.sleep(nSecond); {uuvgFC
} I6,sN9` K
catch(Exception e) 6mbHfL>cO
{ @dp1bkU
e.printStackTrace (); qvhol
} RXU#.=xvy
} )./.rtP|4
BdZO$ALXL
//日志 PM!7ci
public static void log(String sMsg) sT"h)I)]*
{ =D6H?K-k!
System.err.println(sMsg); C>*]a(5k
} (Jb[_d*
l\Or.I7n
t?R=a-ZI
public static void log(int sMsg) "7tEk<x
{ 7Vxe]s
System.err.println(sMsg); {|Pz9a-:
} fG\]&LFBU
} |xQq+e}l<
W9ewj:4\0
Obm@2;^g6
/* M:OJL\0
**TestMethod.java 9AROvq|#
*/ I+^B]@"
package NetFox; 9#AsSbBpf
@43o4,
RU^lR8;
public class TestMethod { [F<Tl =
c(<,qWH
HN*w(bROr
public TestMethod() 'hM?J*m
{ ///xx/weblogic60b2_win.exe ^"d!(npw
try{ ^v].mV/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k$7@@?<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !B_?_ a
SiteFileFetch fileFetch = new SiteFileFetch(bean); <NO?B+ ~]
fileFetch.start(); #e:*]A'I
} &i~AXNw
catch(Exception e){e.printStackTrace ();} De*Z UN|<
n|oAfJUk,
T8i9
} @BZ6{@*
Q`]El<$
kFG>Km(y}
public static void main(String[] args) hp E?
{ vZns,K#4H\
new TestMethod(); uUczD 8y
} R.EA5X|_
} &)p/cOiV
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