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)); NwvC[4
} ,/2Vt/lt
for(int i=0;i<nEndPos.length-1;i++) RSRS wkC
{ An0|[uWH
nEndPos = nStartPos[i+1]; \?-<4Bc@
} 4k1xy##
nEndPos[nEndPos.length-1] = nFileLength; J!(<y(l
} G>}255qY
} .2t4tb(SUw
AV]2euyn
:eCwY
//启动子线程 JyK3{wYS
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3;9^
for(int i=0;i<nStartPos.length;i++) cqkV9f8Ro
{ V2EUW!gn 2
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), !9e=_mY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ~G&dqw/.-U
nStartPos,nEndPos,i); `/+>a8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \*?~Yj#
fileSplitterFetch.start(); Ic<2QknmP
} Wvh#:Z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _4~+{l+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Q3~H{)[Kq
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Nh|uO?&C6
nEndPos = " + nFileLength); =y*IfG9b
// fileSplitterFetch[nPos.length-1].start(); t{9GVLZ
0Mm)`!TLSW
eo?bL$A[s
//等待子线程结束 ;igIZ$&
//int count = 0; c)85=T6*aA
//是否结束while循环 sll\g
boolean breakWhile = false; ]F~dlH1Wp
="H`V V_
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while(!bStop) |HQW0
{ M|h3Wt~7
write_nPos(); !f[_+CD
Utility.sleep(500); @,+5y\]C
breakWhile = true; PC8Q"O
<kqo^
hn@08t G
for(int i=0;i<nStartPos.length;i++) cV6D<,)
{ C}Cs8eUn
if(!fileSplitterFetch.bDownOver) =UQ3HQD
{ Btn?N
breakWhile = false; 7n<{tM
break; !Ai@$tl[S
} [9L:),&u
} FW4<5~'
if(breakWhile) W{+2/P
break; 3nQ`]5.Q w
#c!lS<z
Qw*|qGvy^
//count++; C&%_a~
//if(count>4) f$$/H>MJ
// siteStop(); "KpGlY?^
} H7n>Vx:L-
Q)h(nbbVak
C1)!f j=
System.err.println("文件下载结束！"); J ZS:MFA
} 1))8 A@,
catch(Exception e){e.printStackTrace ();} oG\Vxg*
} H1./x6Hr
S=5o < 1
lL3U8}vn
//获得文件长度 *g2x%aZWbG
public long getFileSize() Jnov<+
{ T8$y[W-c
int nFileLength = -1; V 5mTP'
try{ u6JM]kR
URL url = new URL(siteInfoBean.getSSiteURL()); V)25$aKW7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }Sv:`9=
httpConnection.setRequestProperty("User-Agent","NetFox"); Y$_B1_
wc4=VC"y
0GeTSFj
int responseCode=httpConnection.getResponseCode(); WOap+
if(responseCode>=400) GD$l||8
{ )y$(AJx$
processErrorCode(responseCode); #"~<HG}bR/
return -2; //-2 represent access is error qX{+oy5
} li.;IWb0+)
" H\k`.j
UCjld
String sHeader; n:!_
`|q(h Ow2
~]2K^bh8&
for(int i=1;;i++) + ePS14G
{ .ioEIsg
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); hwv/AnX~O
//Utility.log(in.readLine()); R\[e!g*I
sHeader=httpConnection.getHeaderFieldKey(i); FZnw0tMq
if(sHeader!=null) 3!]rmZ-W
{ (GfZ*
if(sHeader.equals("Content-Length")) > ~O.@|
{ tWcHb #
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JWxwJex
break; gPPkT"
} ym1Y4,
} @q)d
else P&Vv/D
break; nu%*'.
} wibNQ`4k
} j3Y['xDv
catch(IOException e){e.printStackTrace ();} FYQS)s
catch(Exception e){e.printStackTrace ();} ;2QP7PrSY
|A(Iti{v
]Y&VT7+Z
Utility.log(nFileLength); +ZP7{%
i83OOV$1J
f/?P514h
return nFileLength; r~['VhI!;E
} sW\!hW1*x
Z%UP6%
,ig/s2ZG6X
//保存下载信息（文件指针位置） $XH^~i;
private void write_nPos() Eu3E-K@y
{ Q~9^{sHZjP
try{ `R^gU]Z,
output = new DataOutputStream(new FileOutputStream(tmpFile)); @6-jgw>W2
output.writeInt(nStartPos.length); VIf.q)_k
for(int i=0;i<nStartPos.length;i++) ;O,jUiQ
{ qHsA1<wg
// output.writeLong(nPos); N;%6:I./
output.writeLong(fileSplitterFetch.nStartPos); %?/X=}sE
output.writeLong(fileSplitterFetch.nEndPos); dWBA1p
} m1AJ{cs
output.close(); {)<v&'*c~
} Ow,b^|
catch(IOException e){e.printStackTrace ();} *oix6
catch(Exception e){e.printStackTrace ();} ]Hv[IodJ
} #/37V2E
8u]2xB=K
F!K>Kz
//读取保存的下载信息（文件指针位置） lyhiFkO iH
private void read_nPos() >9J:Uo1z
{ Tlr v={
try{ l'E6CL}@[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .=; ;
int nCount = input.readInt(); `Pnoxm'
nStartPos = new long[nCount]; 9>#6*/Oa7
nEndPos = new long[nCount]; K*dCc}:`
for(int i=0;i<nStartPos.length;i++) @C aG9]
{ G3v5KmT
nStartPos = input.readLong(); %;!.n{X
nEndPos = input.readLong(); \_fv7Fdp{
} |y!A&d=xYn
input.close(); ,/unhfs1q
} DtnEi4h,
catch(IOException e){e.printStackTrace ();} dAj$1Ke
catch(Exception e){e.printStackTrace ();} Znv,9-
} I%Z
3Zh)]^
lu/ (4ED
private void processErrorCode(int nErrorCode) BJ(M2|VH
{ 08{@rOr
System.err.println("Error Code : " + nErrorCode); Etm?'
} g9F?z2^
bg0Wnl
\l3h0R
//停止文件下载 m#p'iU*va,
public void siteStop() T51 `oZ`
{ > Nr#O
bStop = true; _SkLYL!=9
for(int i=0;i<nStartPos.length;i++) akQ7K
fileSplitterFetch.splitterStop(); }ad|g6i`
ovV'VcUs
RG`1en
} =g|FT
} =tY T8Q;al
//负责部分文件的抓取 $ME)#(
**FileSplitterFetch.java IE~ |iQ?-
*/ >LuYHr
package NetFox; ~Cjn7
a[TMDU;(/4
T[j,UkgGo
import java.io.*; ml$o5&sN
import java.net.*; k VQ\1!
rrv%~giU
vfo~27T{(
public class FileSplitterFetch extends Thread { [ikOb8 G#
xId.GWY1
KK &?gTa
String sURL; //File URL A5w6]:f2
long nStartPos; //File Snippet Start Position {VoHh_[5%
long nEndPos; //File Snippet End Position bN@ l?w
int nThreadID; //Thread's ID cN9t{.m
boolean bDownOver = false; //Downing is over J$v?T$LVw
boolean bStop = false; //Stop identical 1-QS~)+
FileAccessI fileAccessI = null; //File Access interface EJ@ ~/)<
~PNub E
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException pD+k*
{ OZ!^ak
this.sURL = sURL; |zE'd!7E
this.nStartPos = nStart; h)nG)|c
this.nEndPos = nEnd; S21,VpW\
nThreadID = id; ^Zp>G{QL{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 dcT80sOC
} L j$;:/G
\nqS+on]
G*v,GR
public void run() ?0xgRe<
{ &jr3B;g!C
while(nStartPos < nEndPos && !bStop) KY]C6kh
{ 1ZRT:N<-
;jTN| i'
9~YMyg(Z
try{ Mb7I[5v
URL url = new URL(sURL); >-{Hyx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); !0E&@X:-
httpConnection.setRequestProperty("User-Agent","NetFox"); ws^ np
String sProperty = "bytes="+nStartPos+"-"; 7J&4akT{9
httpConnection.setRequestProperty("RANGE",sProperty); SK.: Q5:
Utility.log(sProperty); \5cpFj5%
}4S6Xe
;6hOx(>`=
InputStream input = httpConnection.getInputStream(); 2)~> R
//logResponseHead(httpConnection); 1@=po)Hnp
'[O;zJN;
uRe'%?W
byte[] b = new byte[1024]; y18Y:)DkL
int nRead; &G$Ucc `
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 9]@!S|1
{ P L+sR3bR
nStartPos += fileAccessI.write(b,0,nRead); s&J]zb`
//if(nThreadID == 1) R_xRp&5
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .w,q0<}
} S#[j )U-
:p6M=
O<W_fx8_'
Utility.log("Thread " + nThreadID + " is over!"); K'I#W lg
bDownOver = true; ?b5^
//nPos = fileAccessI.write (b,0,nRead); !$>R j
} j$5LN.8J
catch(Exception e){e.printStackTrace ();} eKqk= (
} ymcLFRu,
} i(+p0:< 0
y L~W.H
d8x;~RA
//打印回应的头信息 ?@ $r
public void logResponseHead(HttpURLConnection con) e64^ChCoV
{ Lq!>kT<]!
for(int i=1;;i++) ;P&OX5~V
{ N$:8,9.z
String header=con.getHeaderFieldKey(i); w"&n?L
if(header!=null) J!7MZLb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); S`m]f5u|
Utility.log(header+" : "+con.getHeaderField(header)); BJo*'US-Q
else mU9kVx1+
break; ^L&iR0
} , SnSW-P
} G;XxBA
_2 osV[e
'>C5-R:O
public void splitterStop() yJe>JK~)
{ u08mqEa
bStop = true; qA5r
} t.\dpBq
T37XBg H
%BB%pC
} TrR8?-
w917N4$
j^2j&Ta
/* {+Cy U!O
**FileAccess.java QoH6
*//文件访问(定位，写) @49S`
package NetFox; 0Pi:N{x8
import java.io.*; &~U ]~;@
N_q|\S>t/
y Fq&8 x<X
public class FileAccessI implements Serializable{ ;@E$}*3[>V
LvYB7<zk>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -!]ZMi9
RandomAccessFile oSavedFile; ?p8_AL'RS
long nPos; J`1rJ
V,N%;iB}
t}tEvh
public FileAccessI() throws IOException G?Hdq;
{ K8Y=S12Ti
this("",0); 4)o
} h;NYdX5
@bP)406p
i,9)\1R
public FileAccessI(String sName,long nPos) throws IOException 7EO_5/cY
{ cq4Ipe
oSavedFile = new RandomAccessFile(sName,"rw"); >Wg hn:^
this.nPos = nPos; ls)%c
oSavedFile.seek(nPos); n#_$\ p>Yd
} nwCrZW
&W6^sj*k5U
."y1_dDql
public synchronized int write(byte[] b,int nStart,int nLen) wZZt
{ Rr|VD@%
int n = -1; i@M[>~
try{ Y,zxbXZv'5
oSavedFile.write(b,nStart,nLen); q{;:SgZ
n = nLen; Nf1-!u7
} k7usMVAA
catch(IOException e) a-L;*
{ *,WU?tl&
e.printStackTrace (); fIv*T[
} /FEVmH?
L8#5*8W6
!f&g-V
return n; @/-\k*T
} G{%LB}2
b(O3@Q6[
y:qUn!3
} 7o5BXF
V[vl!XM
s#=7IH30
/* oIj#>1~c%
**SiteInfoBean.java N7R!C)!IL
*/ '}bgLv
package NetFox; ;cN{a&
>[=^_8M
AX/m25x
public class SiteInfoBean { w!clI8v/
ZSd4z:/
Pce;r*9
private String sSiteURL; //Site's URL i9][N5\$
private String sFilePath; //Saved File's Path t"/q]G5
private String sFileName; //Saved File's Name l$bu%SZ
private int nSplitter; //Count of Splited Downloading File #';:2Nyq
xbYi.
dT1H
public SiteInfoBean() 0T5L_%c
{//nSplitter的缺省值为5 UH/\
//default value of nSplitter is 5 ,f;}|d:r
this("","","",5); 2Dj%,gaR
} ~|xA4u5LG
yhA6i
M%;hB*9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) L.0mk_&
{ ]G< Vg5
sSiteURL= sURL; a]tVd#
sFilePath = sPath; Px`!A EFd[
sFileName = sName; ':m,)G5&
this.nSplitter = nSpiltter; ly3\e_z:G
HcSXsF
*CTlOy
} (|1A?@sJ#h
nq8C'Fo!6T
LsS
public String getSSiteURL() ;&-k#PE]/H
{ ; _1 at
return sSiteURL; 7!TueP0Zd
} VrQmP
&t:Gx<]
FNY8tv*/x
public void setSSiteURL(String value) b9<#K+L-
{ t$#jL5
sSiteURL = value; |f_[\&<*
} A*P|e-&Q8
p/@smke
74k dsgQf
public String getSFilePath() p\aaJ
{ @>>~CZ`l
return sFilePath; bsA-2*Q+
} JKmIvZ)8
r{I% \R!@
x!58cS*
public void setSFilePath(String value) Y+u_IJ
{ ly_HWuFJ3
sFilePath = value; 3H6lBF
} K\6u9BYG
!sW(wAy?o
s %\-E9 T
public String getSFileName() [o+q>|q
{ y0.8A-2:
return sFileName; e)#J1(j_
} c*L\_Vx+
iq( E'`d
6){]1h"
public void setSFileName(String value) e-#BDN(O
{ ^pF&`2eD
sFileName = value; QD*35Y!d
} YhE+W
WE.{p>
ll.N^y;a
public int getNSplitter() p(`6hWx
{ ~T,c"t2
return nSplitter; Xe:jAkDp
} Df<xWd2
.|b$NM
K<ft2anY5
public void setNSplitter(int nCount) +kO!Xc%P&
{ l@+7:n4K0
nSplitter = nCount; JJ2_hVU
} sjwo/+2
} 9s$CA4?HP
f"SD/]q-
m\r@@!
/* ^c4@(]v'G
**Utility.java :^WKT
*/ *><F'
package NetFox; ?+W9az]+
b Y\K
4;]hK!AXS
public class Utility { IIF]/Ek]
se>8Z4
hYNY"VB
public Utility() k_5L4c:"
{ ^2on.N q>
:f}9($
kG@@ot" n
} QaS7z#/?.
jW3!6*93
//线程睡眠 v)l8@.
public static void sleep(int nSecond) 6S*exw
{ ?DQsc9y
try{ 2s&*
Thread.sleep(nSecond); J^}V|#
} 4Thn])%I
catch(Exception e) Ix!Iw[CNd
{ `YLD`(\
e.printStackTrace (); D=m9fFz
} [nc4{0aT'
} >x+6{^}Q>
o` ZQd,3
//日志 Dhw(#{N
public static void log(String sMsg) UU mTOJr
{ $M lW4&a|
System.err.println(sMsg); Ax?y
} "UGY2skf;
_w/EP
4UlyxA~
public static void log(int sMsg) w' OXlR
{ r(aLEJ"u?
System.err.println(sMsg); A3no~)wZn
} M/ni6%x
} Jz.NHiLct1
v~V5`%
%Yicg6:
/* -pa )K"z
**TestMethod.java ?_$=l1vf
*/ PMh^(j[
package NetFox; m-*i>4;
EQ`(yj
Y/>&0wj)d
public class TestMethod { X4AyX.p
u7\J\r4,+
/#-C4"|
public TestMethod() \h DdU+
{ ///xx/weblogic60b2_win.exe z4+k7a@jn
try{ d`nVc50
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); XZJ+h,f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); <2|O:G
SiteFileFetch fileFetch = new SiteFileFetch(bean); Q6AC(n@:FV
fileFetch.start(); YN2sdG
} wztA3ZL*W1
catch(Exception e){e.printStackTrace ();} H!nr^l'+
-/cZeQDPb
##;Er47@^
} Xr2ou5zAn
.DR<Te
%K`% *D
public static void main(String[] args) 2H6,'JK@F
{ " '6;/N
new TestMethod(); qg!|l7e
} Bck7\
} m~Bl*`~M
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