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)); {dxFd-K3
} VzXVy)d
for(int i=0;i<nEndPos.length-1;i++) t"B3?<?]
{ Ue \A ,
nEndPos = nStartPos[i+1]; YC1Bgz
} \Vme\Ke*v)
nEndPos[nEndPos.length-1] = nFileLength; |tAkv
} )p>Cf_[.
} v]M:HzP
9`Qa/Y!
z I2DQ] 9
//启动子线程 8gavcsVE[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0U7Gl9~
for(int i=0;i<nStartPos.length;i++) .F,l>wUNe
{ zg ,=A?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &.E/%pQ`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), AO8 #l YP?
nStartPos,nEndPos,i); <}lah%4F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [2,D]e
fileSplitterFetch.start(); I/w;4!+)
} H5 z1_O_+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r[(;J0=
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;h1hz^Wq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Tz)Ku
nEndPos = " + nFileLength); ,marNG
// fileSplitterFetch[nPos.length-1].start(); :,l16{^
ZV--d'YiEm
Jk%5Fw0
//等待子线程结束 |fKT@2(
//int count = 0; ^##j {h7
//是否结束while循环 a]*{!V{$i
boolean breakWhile = false; 9}QIqH\p
z6)N![X
UJ,vE}=_{
while(!bStop) Lk|`\I T
{ f+9WGNpw
write_nPos(); E"'u2jEG^
Utility.sleep(500); pyV`O[
breakWhile = true; #M~yt`R~
+\ftSm>
s=:)!M.i
for(int i=0;i<nStartPos.length;i++) -r,v3n
{ [s$x"Ex
if(!fileSplitterFetch.bDownOver) ?;oJ=.T
{ `xx.,;S
breakWhile = false; B>1,I'/$.
break; (W#CDw<ja
} 4 xqzdR_
} 07Yak<+~
if(breakWhile) w)|9iL8
break; pfZ[YC-
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'4M{Xn}@
//count++; m!KEK\5M?
//if(count>4) NxF:s,a6
// siteStop(); g$NUu
} x:0swZ5Z
AM=> P7
d;<'28A
System.err.println("文件下载结束！"); \FfqIc9;
} +@]k[9
catch(Exception e){e.printStackTrace ();} 8o+:|V~X
} hdWVvN
8?8V;
0S:&wb
//获得文件长度 ,y'6vW`%g9
public long getFileSize() @k{q[6c2n
{ 9n is8
int nFileLength = -1; $VQ;y|K+[
try{ DTH}=r-
URL url = new URL(siteInfoBean.getSSiteURL()); p>eYi \'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R`]@.i4tt
httpConnection.setRequestProperty("User-Agent","NetFox"); 8x-19#
/fUdb=!Z
cWo>DuW&
int responseCode=httpConnection.getResponseCode(); Rd HCbk
if(responseCode>=400) ~S<aIk0l
{ hiibPc?I
processErrorCode(responseCode); omg#[
return -2; //-2 represent access is error Yr"Of*VNH
} QOK,-
c $r"q :\
E[#VWM I
String sHeader; SrH::-{
h!uyTgq
Y=|p}>.}
for(int i=1;;i++) :l"BNT[/
{ U"/T`f'H z
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); "Y^j=?1k
//Utility.log(in.readLine()); Zoxblk
sHeader=httpConnection.getHeaderFieldKey(i); eCR^$z=c
if(sHeader!=null) r+m.!+
{ =8#.=J[/
if(sHeader.equals("Content-Length")) ,mx\ -lWFy
{ |pS]zD
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); aV7VbC
break; rR":}LA^d
} JwxKWVpWv
} )NhC+=N
else N$Ad9W?T
break; 5.ab/uk;M
} @:RoYvk$
} E9mu:T
catch(IOException e){e.printStackTrace ();} h2x9LPLBxT
catch(Exception e){e.printStackTrace ();} .s>@@m-
,9d]-CuP;
*Sdx:G~gp
Utility.log(nFileLength); cH*")oD
@.$- ^-
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return nFileLength; n%29WF6Zf
} )V~=B]
4v/MZ:%C`
l!XCYg@67
//保存下载信息（文件指针位置） @Ol(:{<
private void write_nPos() t O.5
{ !AJkd.
try{ -5
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~5N oR
output.writeInt(nStartPos.length); _f";zd
for(int i=0;i<nStartPos.length;i++) B<L7`xL
{ 9tv,,I;iU
// output.writeLong(nPos); bwhH2^ !
output.writeLong(fileSplitterFetch.nStartPos); q++\<\2
output.writeLong(fileSplitterFetch.nEndPos); n_; s2,2r
} $.C-_L
output.close(); m W>Iib|
} >v, si].
catch(IOException e){e.printStackTrace ();} 6\I^]\YO
catch(Exception e){e.printStackTrace ();} $adZ|Q\
} tqpO3
@Q,Q"c2
\~A qA!)6
//读取保存的下载信息（文件指针位置） ^CLQs;zXE
private void read_nPos() !@ ]IJ"\
{ *GoTN
try{ r!fUMDS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 2#:p:R8I>
int nCount = input.readInt(); M5w/TN
nStartPos = new long[nCount]; r@C~_LgL)
nEndPos = new long[nCount]; Dq~;h \='
for(int i=0;i<nStartPos.length;i++) 1xEOYM)
{ =q]!"yU[d
nStartPos = input.readLong(); I ?Dp*u*
nEndPos = input.readLong(); ;6``t+]q
} Z6${nUX
input.close(); Ur]$@N
} #0T/^ #
catch(IOException e){e.printStackTrace ();} hT1JEu
catch(Exception e){e.printStackTrace ();} FfM^2`xP
} MZ$uWm`/
TMMJ5\t2
5\z<xpJ
private void processErrorCode(int nErrorCode) CnL=s6XD'
{ H}kSXKO8!8
System.err.println("Error Code : " + nErrorCode); MuOKauYa
} nyi!D
tXtNK2-1
f%.Ngf9
//停止文件下载 [HYr|T
public void siteStop() LWJ ?p-X
{ '42$O
bStop = true; f0SrPc v
for(int i=0;i<nStartPos.length;i++) bD,X.
fileSplitterFetch.splitterStop(); pml33^*<U
g=4^u*
Gu~*ZKyJ
} aA#79LS
} ~5&4s
//负责部分文件的抓取 1b1Ab zN
**FileSplitterFetch.java tjFX(;^[
*/ V>T?'GbS
package NetFox; ~C%I'z'
nI]EfHU
:1UMA@HP
import java.io.*; 8lpAe0p(Z
import java.net.*; O_1[KiZ
X8ap
z5$Q"Y.D
public class FileSplitterFetch extends Thread { A`Dx]y
:CE4< {V
KL=<s#
String sURL; //File URL \wA:58 -j
long nStartPos; //File Snippet Start Position 0pMN@Cz6
long nEndPos; //File Snippet End Position ` 'Qb?F6
int nThreadID; //Thread's ID K2M=)B
boolean bDownOver = false; //Downing is over Oh$:qu7o0&
boolean bStop = false; //Stop identical D`WRy}o
FileAccessI fileAccessI = null; //File Access interface P!|Z%H
PX|@D_%Y=
&$/ #"lW,V
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d)vP9vXy
{ nte?a e
this.sURL = sURL; K#Ck,Y"
this.nStartPos = nStart; HCN/|z1Xq
this.nEndPos = nEnd; *z VN6wG{
nThreadID = id; qMJJBl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 viAAb
} yV8J-YdsG
L_!ShE
oVy{~D=
public void run() O<cP1TF
{ ;`#R9\C=h
while(nStartPos < nEndPos && !bStop) :Mu*E5
{ swF{}S"
bOj)Wu
VdK%m`;2
try{ NV4g5)D&L
URL url = new URL(sURL); -Ty~lZ)TDT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !}TsFa
httpConnection.setRequestProperty("User-Agent","NetFox"); {3`385
String sProperty = "bytes="+nStartPos+"-"; 4=tR_s
httpConnection.setRequestProperty("RANGE",sProperty); +>q#eUS)
Utility.log(sProperty); :_R:>n9 p
JaY"Wfc
12n:)yQy
InputStream input = httpConnection.getInputStream(); &Pr\n&9A
//logResponseHead(httpConnection); uAPVR
:82h GU
#; ?3kuq(
byte[] b = new byte[1024]; xrkl)7;
int nRead; E7A!,A&>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }'x;J
{ GkJcd;
nStartPos += fileAccessI.write(b,0,nRead); Zl5'%b$&
//if(nThreadID == 1) @zg}x0]
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hN'])[+V
} Tsg9,/vXM
XH!#_jy
KRaL+A
Utility.log("Thread " + nThreadID + " is over!"); .ImaM
bDownOver = true; cFL~< [>_
//nPos = fileAccessI.write (b,0,nRead); ZkbE&7Z
} !y_{mE?V(
catch(Exception e){e.printStackTrace ();} |Ghk8 WA
} Q6Gw!!Z5EA
} /IpCo
;>?h/tS6
Ki;SONSV~|
//打印回应的头信息 7s(tAbPdB
public void logResponseHead(HttpURLConnection con) 92DM1~ *
{ ss)x fG
for(int i=1;;i++) dDPQDIx
{ _B^zm-}8|B
String header=con.getHeaderFieldKey(i); @oAz
if(header!=null) T^}UE<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~gfR1SE
Utility.log(header+" : "+con.getHeaderField(header)); >c,s}HJ
else 'Z`7/I4&
break; !K>iSF<
} KMRPleF
} =5+*TL`
7<yc:}9nx
LCHMh6
public void splitterStop() (wDE!H7
{ GI%&.Vd
bStop = true; F_ F"3'[
} cszvt2BIg
sAkr-x?+M
J$3g3%t
} @ma(py
5WQl?yMP
kTvM,<
/* D4=*yP
**FileAccess.java 79h~w{IT@
*//文件访问(定位，写) fW-C`x
package NetFox; ShB]U5b:k
import java.io.*; .;?!I_`
eTuqK23
I^?tF'E
public class FileAccessI implements Serializable{ kU<t~+
l[}4 X/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c2npma]DZ
RandomAccessFile oSavedFile; tq3_az ~1
long nPos; y}odTeq
C ^Y\?2h1
8-2`S*
public FileAccessI() throws IOException 4V,.Oi
{ $GJT
this("",0); x|6]+?l@6
} wX,V:QE
<g[z jV9p
%nZl`<M
public FileAccessI(String sName,long nPos) throws IOException {a7~P0$
{ xe`^)2z
oSavedFile = new RandomAccessFile(sName,"rw"); vi,hWz8WB
this.nPos = nPos; 7j]v_2S`
oSavedFile.seek(nPos); ~e{ @5.g
} 1 R5pf
ZwmucY%3
-#|D>
public synchronized int write(byte[] b,int nStart,int nLen) NQ9v[gv
{ kka5=u
int n = -1; ;5Sdx5`_
try{ @]=40Yj~w
oSavedFile.write(b,nStart,nLen); WgtLKRZ\
n = nLen; $]2)r[eA)
} jJ,_-ui
catch(IOException e) 1+x" 5<(W
{ QU).q65p
e.printStackTrace (); jj5S+ >4
} EApKN@<"
b^1QyX^?:
eVXXn)>
return n; F-yY(b]$
} D|;O9iks#
*%j$i_
-=ZL(r 1
} .G0 N+)
Luq4q95]
7;'33Bm*
/* y~SVD@
**SiteInfoBean.java J+6zV m
*/ .JhQxXj
package NetFox; _P;D.>?
[,zq
uw)7N(os\`
public class SiteInfoBean { ym%UuC3^w
&gXh:.
4QL>LK
private String sSiteURL; //Site's URL '%NglC[J
private String sFilePath; //Saved File's Path AU{"G
private String sFileName; //Saved File's Name fr@F7s5}
private int nSplitter; //Count of Splited Downloading File 7},A.q
=CX1jrLZ
^kez]>
public SiteInfoBean() rd%%NnT"
{//nSplitter的缺省值为5 )#=J<OpG
//default value of nSplitter is 5 ]\$/:f-2
this("","","",5); +#W94s~0V
} Gz[yD ~6a
r~4uIUE{
7u):J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rO1!h%&o"
{ 3*b5V<}'|
sSiteURL= sURL; V$^jlWdR
sFilePath = sPath; 4=zs&
sFileName = sName; )9QtnM
this.nSplitter = nSpiltter; qNp1<QO0
#&Sr;hAJ
K2
} {$*N1$(%
(i1JRn-f
e[S`Dm"i)'
public String getSSiteURL() 8.E"[QktZ
{ x%{]'z
return sSiteURL; $pGT1oF[E
} @f!X%)\;x
<n"BPXF~
U|(+-R8Z
public void setSSiteURL(String value) bz>X~
{ em$pU*`P
sSiteURL = value; O] _4pP
} W U(_N*a
x&}]8S)
1H)mJVIKkB
public String getSFilePath() nB[-KS
{ JzHG5nmB
return sFilePath; NW3c_]`=
} 4zug9kFK
my=f}%k=
RaZ>.5 D
public void setSFilePath(String value) 92+8zX
{ c\bL_
sFilePath = value; Ucj?$=
} ZykMri3bi
cs9^&N:w[
v9$!v^U"D
public String getSFileName() rr<E#w
{ >ZA=9v
return sFileName; bp1AN9~
} .8hI ad
+/:tap|V
C*9X;+S0J
public void setSFileName(String value) 1I+9?fa
{ :FyF:=
sFileName = value; 9 _d2u#
} >yIJ8IDF
xo:kT)
hy;VvAH5
public int getNSplitter() IRdt:B|@
{ O 4 !$
return nSplitter; E+td~&x
} hbjAxioA
*[Hrbln
#;!&8iH
public void setNSplitter(int nCount) 'sNZFB#
{ S63Zk0(25
nSplitter = nCount; )Q)qz$h@
} 6CJMQi,kn
} 8;PkuJR_]
yNTd_XPL
DE?v'7cmA
/* &W `xZyb3
**Utility.java R>Ra~b
*/ 9KSi-2?H
package NetFox; _IH" SVub
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%H{p&ms
public class Utility { |HazM9=
xO$P C,
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public Utility() R1jl<=
{ pYO =pL^Q
\& JZ >h
qnm_#!&uHT
} (8nv&|
]@q%dsz
//线程睡眠 xNz(LZ.c
public static void sleep(int nSecond) #-hO\ QdC
{ v=`yfCX-qX
try{ x2"iZzQlD
Thread.sleep(nSecond); LQ0/oYmNc
} yNu_>!Cp5
catch(Exception e) ?^|`A}q#
{ h8rW"8Th
e.printStackTrace (); Bx\&7|,x
} V0ze7tSG[f
} 8^mE<
$KHm5*;nd
//日志 kmB!NxF>)F
public static void log(String sMsg) !^J;S%MB:K
{ !iXRt")
System.err.println(sMsg); \1EuHQ?
} b*|~F
7Z-j'pq
Z%T Ajm
public static void log(int sMsg) SnCwoxK
{ g40Hj Y
System.err.println(sMsg); OATdmHW
} jm0p%%z
} _=v#"l
+z >)'#
OG\i?N
/* )0{`}7X
**TestMethod.java QV4|f[Ki%
*/ m0HK1'
package NetFox; .hTqZvDa
Q=~"xB8
PK*Wu<<
public class TestMethod { \0$+*ejz
Q PH=`s
A=|XlP$6
public TestMethod() _0H oJ
{ ///xx/weblogic60b2_win.exe UBvp32p
try{ i,Ct AbMx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); uo F.f$%"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^$c#L1 C
SiteFileFetch fileFetch = new SiteFileFetch(bean); |OQ]F
fileFetch.start(); 8f@}-
} .?>Cav9:
catch(Exception e){e.printStackTrace ();} rb?7i&-
<O#&D|EMd|
^BsT>VSH6
} *dBy<dIy
3bEcKA_z(
d\z6Ob"t
public static void main(String[] args) =j7Du[?Vu
{ dab]>% M
new TestMethod(); -YoL.`s1
} w,{h9f
} 6jE.X
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