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)); Za?BpV~
} >bI\pJ
for(int i=0;i<nEndPos.length-1;i++) pm9sI4S
{ A.yIl`'UP#
nEndPos = nStartPos[i+1]; t(vyi
} \'zloBU
nEndPos[nEndPos.length-1] = nFileLength; Jj0:p"
} \d.\M
} 'ahz@+lO
@:Ft+*2
A:4&XRYZY
//启动子线程 ?ecR9X k
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~("bpS#ZgD
for(int i=0;i<nStartPos.length;i++) -ert42fN
{ ,+Ocb-*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3=?,Dv0P
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), InRRcn(
nStartPos,nEndPos,i); =/xx:D/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mm*nXJ
fileSplitterFetch.start(); uwi.Sg11
} 4Q1R:Ra
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X]2x0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ,*9gy$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zgGJ<=G.
nEndPos = " + nFileLength); YADXXQ"
// fileSplitterFetch[nPos.length-1].start(); UCj<FN `
YuHXm3[
=b"{*Heuw
//等待子线程结束 gw">xt5
//int count = 0; RH7!3ye
//是否结束while循环 s^.tj41Gx}
boolean breakWhile = false; t+pA9^$[`
`WMU'ezF
Z;tWV%F5
while(!bStop) ~$//4kES
{ JSylQ201
write_nPos(); {md5G$*%
Utility.sleep(500); MLiaCG;
breakWhile = true; hhWy-fP#
\QG2V$
9GT}_ ^fb
for(int i=0;i<nStartPos.length;i++) wSM(!:on5
{ B+jh|@-
if(!fileSplitterFetch.bDownOver) 8$RiFD,
{ B>I:KGkV
breakWhile = false; _d^d1Q}V
break; I(k(p\l%
} $tc1te
} *5XOYb?'v.
if(breakWhile) xDPR^xY
break; "~zLG"
UxF9Ko( ]d
sV0NDM0
//count++; $*:$-
//if(count>4) w/PE)xA
// siteStop(); Lr d-
} II=!E
VV54$a
9pr.`w
System.err.println("文件下载结束！"); f)Y~F/[$P
} :AQ9-&i/a-
catch(Exception e){e.printStackTrace ();} 0`v-pL0|
} #Jp|Cb<qx
=w:)AWZ
o9C#5%9
//获得文件长度 OTAe#]#
public long getFileSize() O:~J_Wwl!
{ Q`;eI a6U
int nFileLength = -1; OZz!8-|wE
try{ r=7!S8'
URL url = new URL(siteInfoBean.getSSiteURL()); `}L{gssv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )J+A2>
httpConnection.setRequestProperty("User-Agent","NetFox"); ^wwS`vPb
@Jqo'\~&
M} ri>o
int responseCode=httpConnection.getResponseCode(); d.Ccc/1-
if(responseCode>=400) mC-wPi8
{ @CxgoX^
processErrorCode(responseCode); LylCr{s7
return -2; //-2 represent access is error Xx2t0AIB
} !)`*e>]x
D6fd(=t1Z
'qG-)2 t
String sHeader; /?b{*<TK
zMO#CZ t
[~G1Rz\h
for(int i=1;;i++) Hr7pcz/#l
{ 0ZLLbEfnPB
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4pelIoj
//Utility.log(in.readLine()); ^K4?uABc
sHeader=httpConnection.getHeaderFieldKey(i); yh|+Usa
if(sHeader!=null) 9:=:P>
{ je3Qq1
if(sHeader.equals("Content-Length")) tJ8:S@E3,
{ ,!PV0(F(
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B&1E&Cv_8
break; f87XE";:A
} s%>8y\MaK
} .N#KW
else >M##q?.
break; vCK+v r!
} "3a}~J<g
} )iK:BL*Nw
catch(IOException e){e.printStackTrace ();} cW"DDm g
catch(Exception e){e.printStackTrace ();} jP2#w{xq
|b^UPrz)VS
$A/?evJi8R
Utility.log(nFileLength); a"t~K
4%_xTo
.!i`YT*jF
return nFileLength; wa`c3PQGu
} >p;&AaXkoG
;KEie@Ry
k\dPF@~Hvl
//保存下载信息（文件指针位置） ]$sb<o .a
private void write_nPos() &"27U
{ ~Je40vO[
try{ :V@)A/}uk
output = new DataOutputStream(new FileOutputStream(tmpFile)); PDz:x4A
output.writeInt(nStartPos.length); UlNV%34"
for(int i=0;i<nStartPos.length;i++) mI:^lp
{ R7!v=X]i
// output.writeLong(nPos); ?2\oi*$
output.writeLong(fileSplitterFetch.nStartPos); Qgv g*KX
output.writeLong(fileSplitterFetch.nEndPos); D/;[x{;E
} YTTij|(
output.close(); G-R83Orl
} Ai^0{kF6
catch(IOException e){e.printStackTrace ();} JL{fW>5y|
catch(Exception e){e.printStackTrace ();} J~oxqw}
} 2dHsM'ze
x'OP0],#
* {~`Lw)y
//读取保存的下载信息（文件指针位置） ]%FP*YU4O
private void read_nPos() f4F%\ "
{ n6M#Xc'JA
try{ s_+.xIZ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F;kKn:XL
int nCount = input.readInt(); )`ixT)
nStartPos = new long[nCount]; C@zG(?X
nEndPos = new long[nCount]; N^PkSf[)h5
for(int i=0;i<nStartPos.length;i++) @$;8k }
{ =VT\$ 5A
nStartPos = input.readLong(); Qnt9x,1m_
nEndPos = input.readLong(); #Q-#7|0&
} /`nkz
input.close(); '$'a .q1q9
} Zs-lN*u7.
catch(IOException e){e.printStackTrace ();} (\r^0>H
catch(Exception e){e.printStackTrace ();} /0fHkj/J=B
} L%<]gJtrO
ZJF+./vN
`g)
private void processErrorCode(int nErrorCode) B*Om\I
{ HVhd#Q;
System.err.println("Error Code : " + nErrorCode); UugR
} K=}Eupn=
v&d'ABeT
2mMi=pv9
//停止文件下载 ,=c(P9}^
public void siteStop() Q>9bKP
{ %X}vuE[[UC
bStop = true; j8PeO&n>
for(int i=0;i<nStartPos.length;i++) !>=lah$&
fileSplitterFetch.splitterStop(); U /~uu
q8;MPXSG3
^q0`eS
} 4sRg+mMI
} HY?#r]Ryt
//负责部分文件的抓取 C]l)Pz$
**FileSplitterFetch.java bmi",UZ:F
*/ yHlQKI
package NetFox; 11Qi _T\
pzUr9
~ qaT jSP
import java.io.*; *tk=DsRW
import java.net.*; .O(9\3q\
1LhZmv
h(J$-SUs
public class FileSplitterFetch extends Thread { C&%NO;Ole
gyV`]uqG
7N@[Rtv
String sURL; //File URL NXDkGO/*
long nStartPos; //File Snippet Start Position kdx06'4o
long nEndPos; //File Snippet End Position *A8Et5HAv
int nThreadID; //Thread's ID XP:fL NpQ
boolean bDownOver = false; //Downing is over 'irwecd8
boolean bStop = false; //Stop identical BYHyqpP9
FileAccessI fileAccessI = null; //File Access interface GM1.pVb
n9k
Nh/i'q/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException *qAG0EM|
{ vWrTB
this.sURL = sURL; ?EPHq, E
this.nStartPos = nStart; WS(m#WFQr
this.nEndPos = nEnd; f8=qnY2j
nThreadID = id; d#$Pf=}
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v.vkQQ0[9
} 7+@-mJMP$D
&2[Xu4*
L:mE)Xq2
public void run() L;L_$hu)
{ 3O1Lv2)_
while(nStartPos < nEndPos && !bStop) 2EN}"Du]mj
{ Ui9;rh$1eU
I.|b:c xN
;L#RFdh
try{ B]}gfVO
URL url = new URL(sURL); a}|<*!4zUQ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9IrCu?n9b
httpConnection.setRequestProperty("User-Agent","NetFox"); Mqk|H~l5c
String sProperty = "bytes="+nStartPos+"-"; 9 BU#THDm
httpConnection.setRequestProperty("RANGE",sProperty); Eyk:pnKJb
Utility.log(sProperty); /YU8L
2Q@Jp`#,4
h8Oj E$ H
InputStream input = httpConnection.getInputStream(); J(maJuY
//logResponseHead(httpConnection); y;4g>ma0
3 Fy CD4#
H.C*IL9
byte[] b = new byte[1024]; +Zr~mwM=x
int nRead; 4KSq]S.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &+ PVY>q
{ :pz@'J
nStartPos += fileAccessI.write(b,0,nRead); nnE'zk<"
//if(nThreadID == 1) V=5*)i/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); CyHHV
} +/kOUz/]
B B'qbX3xK
Ie=gI+2
Utility.log("Thread " + nThreadID + " is over!"); K"5q387!
bDownOver = true; c+T`X?.j
//nPos = fileAccessI.write (b,0,nRead); YRf$?xa
} +oO7UWs>6
catch(Exception e){e.printStackTrace ();} $]}K;
} ;#IrHR*Bk
} K7(k_4
>hq{:m
O'#;Ge/,
//打印回应的头信息 j%Z5[{!/,X
public void logResponseHead(HttpURLConnection con) C2=PGq
{ 0+SZ-]
for(int i=1;;i++) h"Wpb}FT
{ *<SXzJ(
String header=con.getHeaderFieldKey(i); yM9>)SE5`
if(header!=null) ~UQ<8`@a
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5!$sQ@#}D
Utility.log(header+" : "+con.getHeaderField(header)); +opym!\
else hJSWh5]
break; YDYNAOThnb
} f?GoBh<
} /-^J0f+l3
@(E6P;+{
&2 *
public void splitterStop() KHC Fz
{ Qy4Pw\
bStop = true; 0:4>rYBC
} _K'Y`w']
\+Y=}P>
;pOV; q3j
} "*l{ m2"
-a~n_Z>_
,D(Bg9C
/* ePv`R'#
**FileAccess.java (V'w5&f(L
*//文件访问(定位，写) WS.g`%
package NetFox; P_8!Gp
import java.io.*; Z02EE-A
xw_$1 S
TqV^\C?
public class FileAccessI implements Serializable{ \ISg6v{/
`nEqw/I
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 f O+lD
RandomAccessFile oSavedFile; ?Ov~\[) F
long nPos; T@#?{eA
8*{jxN'M
Ars*H,9>e
public FileAccessI() throws IOException f2SJ4"X
{ 4@<wN \'
this("",0); xE!0p EHd
} 8@S]P0lk
U#iW1jPE2
'o0o.&/=
public FileAccessI(String sName,long nPos) throws IOException F|.tn`j]U
{ M}CxCEdDB]
oSavedFile = new RandomAccessFile(sName,"rw"); $9X?LGUz
this.nPos = nPos; #^9k&t#!6
oSavedFile.seek(nPos); /iQh'rp
} J>;r(j
<6,,:=#
h>cjRH?e
public synchronized int write(byte[] b,int nStart,int nLen) cT/mi":8{
{ %0}}Qt
int n = -1; 2DJg__("
try{ L;{{P7
oSavedFile.write(b,nStart,nLen); d=uGB"
n = nLen; Fi;OZ>;a
} ru`U/6n
catch(IOException e) 3#]IIj`\
{ >m<T+{`
e.printStackTrace (); E?KPez
} VSV]6$~H
YPY,gR
7j&EQm5\9
return n; Yjd/
} _G.!^+)kEm
Ef?|0Gm
lVd-{m)
} U,6sR
,`YBTU
\QF0(*!!
/* D Y4!RjJ47
**SiteInfoBean.java Gx}`_[-
*/ r#&JfAo
package NetFox; &V+KM"Ow
X%(NI(+x,
Ej6ho0_
public class SiteInfoBean { @)[8m8paV
?K2}<H-
cTRtMk%^
private String sSiteURL; //Site's URL QUvSeNSp
private String sFilePath; //Saved File's Path %N(>B_t\
private String sFileName; //Saved File's Name #9.%>1{6Y
private int nSplitter; //Count of Splited Downloading File t?Qbi)T=z
uWFyI"
;PU'"MeB "
public SiteInfoBean() +_bxza(ma{
{//nSplitter的缺省值为5 JEWc{)4QD
//default value of nSplitter is 5 j&a\ K}U!
this("","","",5); )8aHj4x
} Ty~z%=H
.\ya
WQiRbbX
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5/h-Hr
{ T{`VUS/
sSiteURL= sURL; j;z7T;!i
sFilePath = sPath; 7gB?rJHV,
sFileName = sName; ) )FLM^dj
this.nSplitter = nSpiltter; I^u~r.
l`A&LQ[
t?PqfVSq
} ScD E)r
=>evkaj
mXS]SE
public String getSSiteURL() KfZb=v;-l
{ 3RvDX p
return sSiteURL; mv~?1aIKD
} zb"4_L@m2
PeqW+Q.
3tJfh=r=1
public void setSSiteURL(String value) !~R<Il|B
{ %eIaH!x:
sSiteURL = value; wF%RM$
} fc<y(uX
3"v>y]$U
']I!1>v$[
public String getSFilePath() o,c}L9nvt
{ GRkN0|ovfj
return sFilePath; rWDD$4y
} $ xHtI]T
ePJ_O~c
"M /Cl|z
public void setSFilePath(String value) JR15y3F
{ kN{$-v=K
sFilePath = value; aT}Hc5L,b
} v7KBYN
bolG3Tf|
9\WtcLx
public String getSFileName() t1J3'lS
{ |3T2}ohrr
return sFileName; sP2Uj
} W}3%BWn
_Y]Oloo('
zp}pS2DU
public void setSFileName(String value) D&o\q68W
{ ~TS!5Wiv
sFileName = value; wuYak"KX
} 1;S?9N_B
tD}-&"REP
"JLE
public int getNSplitter() \~+b&
{ 4uMMf
return nSplitter; cb0rkmO
} 4 ?PB Fbd
D&uaA-;s
,]:<l
public void setNSplitter(int nCount) ,tg]Gt
{ F!u)8>s+z{
nSplitter = nCount; {6RA~
} 'Rsr*gX#
} v^s?=9
7.ein:M|CB
N'&>bO?@`
/* l1]{r2g
**Utility.java 6Y,&q|K
*/ /}6y\3h
package NetFox; H'/V<%
KGo^>us
#rGCv~0*l
public class Utility { K39I j_3
%r.C9
O|=?!|`o
public Utility() JBJ?|}5k4c
{ U; <{P
o&@y^<UQ
047PlS
} Cu24xP`
LK*9`dzv=G
//线程睡眠 g4Dck4^!4
public static void sleep(int nSecond) ~'0n ]Fw
{ PHIc7*_
try{ N: 38N
Thread.sleep(nSecond); w~crj$UM
} sg}<()
catch(Exception e) N2[jBy8M
{ l$c/!V[3
e.printStackTrace (); xy!E_CuC$
} ELMz~vp
} )T gfd5B
o_Y?s+~i[/
//日志 x$TLj
public static void log(String sMsg) fB]2"(
{ LCA+y1LP-_
System.err.println(sMsg); (yd(ZY
} %_p]6doF
:]Om4Q\-#
upk_;ae
public static void log(int sMsg) 40].:9VG
{ M3]eqxLC
System.err.println(sMsg); 9lGa*f)
} G@jx&#v
} 30Qp:_D
)*uotV
f!5w+6(
/* 4A(h'(^7A
**TestMethod.java 5-({z%:P
*/ '3Fb[md54
package NetFox; T7/DH
!~'D;Jh
|)%H_TXTy
public class TestMethod { KY%qzq,n
.Sa=VC?EZ
S-Vxlku]
public TestMethod() y>u|3:z
{ ///xx/weblogic60b2_win.exe ){,Mv:#+T
try{ x.|sCqx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); C;U4`0=8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); a;~< iB;3"
SiteFileFetch fileFetch = new SiteFileFetch(bean); j%Uoigi
fileFetch.start(); gy|o#&e]%
} I*cb\eU8Y
catch(Exception e){e.printStackTrace ();} KE5>O1
.s41Tc5u
Rm$(X5x>o
} Lrr(7cH,
yqtHlz%
Jx`7W1%T
public static void main(String[] args) 2* TIr
{ .Xe_Gp"x
new TestMethod(); w6Mv%ZO_
} D97 vfC
} f;,*P,K
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