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)); @,Iyn<v{B
} `bJ+r)+5
for(int i=0;i<nEndPos.length-1;i++) & bwhD.:=
{ ; SS/bS|
nEndPos = nStartPos[i+1]; 8"zFTP*;u
} d,_Ky#K5b
nEndPos[nEndPos.length-1] = nFileLength; n!r<\4I
} _U"9#<
} Whd2mKwiO
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uq>\pO&P
//启动子线程 /8(\AuDT
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; QyGTm"9l
for(int i=0;i<nStartPos.length;i++) GYX/G>-r
{ s 9Y'MQo*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 02lI-xHe
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Vk/!_)
nStartPos,nEndPos,i); 1FCHqqZ=
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /7nircXj@
fileSplitterFetch.start(); \=O['#
} Y'YvVI
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DRn]>IFU
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); IwfJDJJ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8<Y*@1*j
nEndPos = " + nFileLength); W?n)IBj8
// fileSplitterFetch[nPos.length-1].start(); ya<nD'%9
z)RJUmY3B
JFyw,p&xB
//等待子线程结束 {*Ag[HS0u
//int count = 0; Gd:TM]rJ
//是否结束while循环 H+oQ L(i|_
boolean breakWhile = false; t4RI%m\
&.zG?e.
't+ J7
while(!bStop) g/o@,_
{ `FjU2 O
write_nPos(); J 8z|ua
Utility.sleep(500); "h-G=vo,kl
breakWhile = true; <}@*i
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6`tc]a"#Zb
for(int i=0;i<nStartPos.length;i++) Rd?8LLz
{ ,:I:F
if(!fileSplitterFetch.bDownOver) zPonG d1
{ LRJY63A
breakWhile = false; "G^Z>Z-`
break; E^)>9f7
} mzh8<w?ns
} {<~oa+"
if(breakWhile) $S_xrrE#
break; M x/G^yO9
:7,j%ELic
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//count++; XYi-o][Mf
//if(count>4) ,G q?
// siteStop(); e5g# a}
} "Cj{Z@n
[9wuaw"~[Z
Q"6:W2#v
System.err.println("文件下载结束！"); }de{-
} Yq6e=?-
catch(Exception e){e.printStackTrace ();} <sALA~p|0
} 7Rba@ cs9
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|6cz r
//获得文件长度 PQu_]cXI
public long getFileSize() Ix-bJE6+I,
{ >FVBn;1
int nFileLength = -1; {Dc{e5K
try{ N(6Q`zs
URL url = new URL(siteInfoBean.getSSiteURL()); >1}RiOd3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 4"om;+\
httpConnection.setRequestProperty("User-Agent","NetFox"); I%^Bl:M
K1th>!JW'
6n|R<DO%\
int responseCode=httpConnection.getResponseCode(); :7WeR0*%
if(responseCode>=400) BHNcE*U}@?
{ CAbeb+O
processErrorCode(responseCode); 9J*M~gKbz
return -2; //-2 represent access is error .T2P%Jn.
} pR3@loFQ`o
>@Nn_d
m-<"`:+
String sHeader; X,]E {
LU-,B?1
c:J;Q){Xz
for(int i=1;;i++) '`)r<lYN,
{ T J!d7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A~@u#]]<n
//Utility.log(in.readLine()); (~6D`g`B
sHeader=httpConnection.getHeaderFieldKey(i); W~!uSrY
if(sHeader!=null) lYF~CNvE
{ W Ai91K@
if(sHeader.equals("Content-Length")) d)R7#HLZ7
{ CeZ+!-lG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); S'h{["P~ 0
break; q':P9o*N?
} =tKb7:KU
} &y} ]^wB
else ^$!H|
break; P^)J^{r
} Z\\'0yuY(
} ^Fn~@'
catch(IOException e){e.printStackTrace ();} {o."T/?d'
catch(Exception e){e.printStackTrace ();} _^k9!Vjo
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N!{waPbPi
Utility.log(nFileLength); ,\DSi&T
!,(6uO%
8mmHefZ}2!
return nFileLength; yUyx&Y/
} WZ A8D0[
[X\<C '<
\#hp,XV>
//保存下载信息（文件指针位置） )B!64'|M
private void write_nPos() F?!X<N{
{ 1.U9EuI
try{ 1v?|n8
output = new DataOutputStream(new FileOutputStream(tmpFile)); @ptE&m
output.writeInt(nStartPos.length); S^,q{x*T
for(int i=0;i<nStartPos.length;i++) &gr)U3w
{ 3d>3f3D8;
// output.writeLong(nPos); e8Y;~OAj[
output.writeLong(fileSplitterFetch.nStartPos); <hv {,1p-r
output.writeLong(fileSplitterFetch.nEndPos); aANzL
} !&f>,?wlP
output.close(); (2l?~CaK
} NbyXi3@v
catch(IOException e){e.printStackTrace ();} ;bMmJ>[l-
catch(Exception e){e.printStackTrace ();} `{B<|W$=
} W]-c`32~S
vJ a?5Jr
*#| lhf'
//读取保存的下载信息（文件指针位置） VGVb3@
private void read_nPos() ?r%kif)
{ :~ ; 48m
try{ B.oD9<9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y.6Yl**l
int nCount = input.readInt(); rHMr8,J;
nStartPos = new long[nCount]; &$x1^
nEndPos = new long[nCount]; !D!1%@ e
for(int i=0;i<nStartPos.length;i++) iiWm>yy
{ yQ/E0>Uj!
nStartPos = input.readLong(); Q2 S!}A
nEndPos = input.readLong(); ?kBX:(g
} B=;pwX
input.close(); 5ieF8F%
} ]iHSUP
catch(IOException e){e.printStackTrace ();} =9;2(<A
catch(Exception e){e.printStackTrace ();} }R\;htmc;
} \Q~HL_fy|Y
"c2{n,
]tnf<5x
private void processErrorCode(int nErrorCode) )bkJ['9
{ DZ*m"Bi
System.err.println("Error Code : " + nErrorCode); .271at#-
} p4sU:
;&~9k?v7L
,mY3oyu
//停止文件下载 LV6BSQyQ
public void siteStop() \5q0nB@i5y
{ h)o5j-M>4
bStop = true; G,,7.%eib=
for(int i=0;i<nStartPos.length;i++) -h`[w:
fileSplitterFetch.splitterStop(); iYR`|PJi
#sJL"GB
~1g)4g~
} G1?m}{D)
} Ce.*yO<-
//负责部分文件的抓取 pLtAusx
**FileSplitterFetch.java hVLVMqd
*/ E8Y(C_:s
package NetFox; bH1MDBb2
v9K=\ j
FC&841F
import java.io.*; }u&,;]
import java.net.*; /8Xd2-
<3WaFi u
rT/4w#_3
public class FileSplitterFetch extends Thread { U3rpmml
RGC DC*\
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String sURL; //File URL 032PR;]
long nStartPos; //File Snippet Start Position K[s!3.u
long nEndPos; //File Snippet End Position _uQxrB"9
int nThreadID; //Thread's ID .cCB,re
boolean bDownOver = false; //Downing is over tFrNnbmlQ
boolean bStop = false; //Stop identical \O G`+"|L
FileAccessI fileAccessI = null; //File Access interface _WB*ArR
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dxk~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 1_MaaA;ow"
{ DMpNmF>
this.sURL = sURL; FXO{i:Zo
this.nStartPos = nStart; ^Sj*
this.nEndPos = nEnd; :kw14?]_
nThreadID = id; #Ab,h#f*7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 C[2LP$6*/
} 1yT\|2ARZ%
GW~ZmK
XMi)PXs$
public void run() lDF26<<\`
{ 88~lP7J
while(nStartPos < nEndPos && !bStop) 3^2P7$W=
{ wU(N<9
_]q%Hve
=CGB}qU l0
try{ r6:c<p[c
URL url = new URL(sURL); n\'@]qG)Z4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); c3X8Wi7m
httpConnection.setRequestProperty("User-Agent","NetFox"); csCi0'u
String sProperty = "bytes="+nStartPos+"-"; .~jn N
httpConnection.setRequestProperty("RANGE",sProperty); RAY.]:}jr
Utility.log(sProperty); =qy{8MsjA
a0*qK)gH
)sBbmct_S
InputStream input = httpConnection.getInputStream(); :j[a X7Sq2
//logResponseHead(httpConnection); Y V#|qb
=Xu(Js-
jQRl-[n
byte[] b = new byte[1024]; NoD\t(@h
int nRead; !^_G~`r$2J
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q%\rj?U_
{ jdW#; ]7+y
nStartPos += fileAccessI.write(b,0,nRead); yr,Oq~e
//if(nThreadID == 1) wW1>#F
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .In8!hjYy4
} <h[l)-86
e}bY9
r>.^4Z@
Utility.log("Thread " + nThreadID + " is over!"); kp>AZVk
bDownOver = true; 8iKupaaOX
//nPos = fileAccessI.write (b,0,nRead); 4M3{P
} <F#/wU^9
catch(Exception e){e.printStackTrace ();} f3M~2jbv'p
} kf>L
} 6S6E 1~
g4=6\vg
&Rxy]kBA
//打印回应的头信息 lgei<\6~n5
public void logResponseHead(HttpURLConnection con) g4CdzN~
{ xjO((JC
for(int i=1;;i++) s\dhQZw3
{ $bo 5:c
String header=con.getHeaderFieldKey(i); /Q*cyLv
if(header!=null) m~U2L
//responseHeaders.put(header,httpConnection.getHeaderField(header)); eHQ3K#M#
Utility.log(header+" : "+con.getHeaderField(header)); u[yUUYe
else ?KF.v1w7
break; ]id5jVY
} GFmVR2z_+
} w7Y>B`wm?
\[F4ooe
Ey**j
public void splitterStop() qwmZOR#
{ o])2_e5
bStop = true; xulwn{R s
} xfqW~&
itmQH\9 8
F G5e{
} WeqQw?-
MF%>avRj
wD'LX
/* SYZS@o
**FileAccess.java b*@y/ e\u`
*//文件访问(定位，写) ?iQA>P9B
package NetFox; f7Fr%*cO
import java.io.*; .f~x*@
i~04P
~e@pL*s
public class FileAccessI implements Serializable{ +w'{I`QIL0
jhmWwT/O8^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *[?DnF+
RandomAccessFile oSavedFile; n^m6m%J)
long nPos; Vg^@6zU
+""8aA
JkMf+!
public FileAccessI() throws IOException Mk"V%)1k
{ 2~BId&]
this("",0); A! j4;=}
} <u9U%Vsi
%}%vey
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public FileAccessI(String sName,long nPos) throws IOException Mb#-I GZ
{ ,0=@cJ
oSavedFile = new RandomAccessFile(sName,"rw"); kb>/R/,9
this.nPos = nPos; V$7SVq
oSavedFile.seek(nPos); TtaVvaz~>
} )^o7%KX
QX$i ]y%S
]/y&5X
public synchronized int write(byte[] b,int nStart,int nLen) 3#@ETt0X(
{ "jyh.@<
int n = -1; 38hAguZX
try{ Im\{b=vT
oSavedFile.write(b,nStart,nLen); MxXu&.|_
n = nLen; @'yD(ZMAz
} Y=#g_(4*
catch(IOException e) 4LBMhLy
{ i1#\S0jN
e.printStackTrace (); L*VO2YI
} :"aCl~cy9g
YLfZ;W|6u
f9Hm2wV
return n; {t;{={$
} XNU[\I
O)tZ`X;
>/DyR+?>4
} 2@ <x%T
8R6!SB
JRC+>'}Xj
/* }"'^.FG^_
**SiteInfoBean.java uK`T1*_
*/ p6yC1\U!o
package NetFox; |W/_S^C
Rj|8lK;,
;J[1S
public class SiteInfoBean { wM;9plYlw0
,ij"&XA
45hjN6
private String sSiteURL; //Site's URL Bk~lE]Q3c7
private String sFilePath; //Saved File's Path ,\|W,N}~
private String sFileName; //Saved File's Name T{iv4`'
private int nSplitter; //Count of Splited Downloading File <[H1S@{W
f3+@u2Pv
f@R j;R~Jp
public SiteInfoBean() C#<:x!
{//nSplitter的缺省值为5 XZv(B^
//default value of nSplitter is 5 \I@=EF- &
this("","","",5); 5Z7<X2
} N%A[}Y0;MW
v[_C^;
:/BU-SFK^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .]qj];m
{ $f-f0t'
sSiteURL= sURL; B?nQUIb:
sFilePath = sPath; L>Y>b4oy3
sFileName = sName; O/9dPod
this.nSplitter = nSpiltter; t&SC>8M<
l)glT]G3+
;R E|9GR
} T<|B1jA
>5&'_
(>x4X@b
public String getSSiteURL() 8Vkw vc
{ h7NS9CgO
return sSiteURL; jB*%nB*x
} ZkW,
a{7>7%[
sS,Swgr
public void setSSiteURL(String value) F#X&Tb{
{ -bo5/`x
sSiteURL = value; eU"!X9
} $&96qsr
0sv#* &0=
;^}gC}tq
public String getSFilePath() FY [WdZDZ
{ uoYG@L2
return sFilePath; Cg/L/0Ak
} /2K4ka<?7
=h?WT*
y]B?{m``6
public void setSFilePath(String value) 7u!i)<pn
{ ){|Bh3XV
sFilePath = value; *.0}3
} 1MH[-=[Q
.v36xXK(
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public String getSFileName() \ %Er%yv)
{ {(@M0?
return sFileName; X !g"D6'
} 1D03Nbh|5
|*W`}i
$R3]y9`?
public void setSFileName(String value) 0b9;vlGq$
{ PpD ?TAlA
sFileName = value; nc#}-}`5
} 0Zp) DM
37DyDzW)'
,y}?Z8?63
public int getNSplitter() e`%U}_[d
{ @vdBA hXk
return nSplitter; hA.?19<Z
} Vu '3%~
-y70-K3
Z,%^BAJ
public void setNSplitter(int nCount) 6]yYiz2Xn
{ &FF%VUfQJ
nSplitter = nCount; 96UL](l(`
} ")MjR1p
} .5*h']iFr1
=*7K_M&
{<{ O!
/* !63p?Q=
**Utility.java ct+ ;W
*/ g5X;]%:
package NetFox; ;uj&j1
cRPW
;/w-7O:
public class Utility { QH:k5V~
<rZ(B>$
K' xN>qc
public Utility() 9P;}P!W
{ xT7JGQ[|
P` Hxj> {
InnjZ>$
} @j*K|+X"
(3Hz=k_
//线程睡眠 R57>z`;
public static void sleep(int nSecond) @>n7
{ kR2kV"-l
try{ DPCB=2E
Thread.sleep(nSecond); r(;sX
} n qSjP5
catch(Exception e) ME"B1Se\
{ n1+1/
e.printStackTrace (); ?.tnaE
} ru#,pJ=O(
} p4QQ5O$;
qdkhfm2(K
//日志 Bw _^"e8X
public static void log(String sMsg) 'B dZN
{ Z<L|WRe
System.err.println(sMsg); cPD&xVwq>
} IE7%u92
}71a3EUK
\ng!qN
public static void log(int sMsg) `}t<5_
{ qxKW%{6o
System.err.println(sMsg); {j$:9 H
} 2P3,\L
} [B<htD&
0c6b_%Rd
KE>|,Ur
/* v_M-:e3`
**TestMethod.java xQLVFgd
*/ @r7ekyO8)
package NetFox; Vwxb6,}Z
P2la/jN
bMe/jQuL.$
public class TestMethod { X{cFqW7
gR7in!8
D%[yAr;r
public TestMethod() mX8k4$z
{ ///xx/weblogic60b2_win.exe .[mI9dc
try{ ?8AV-rRX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); v@m2c_,
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sz;B-1^6
SiteFileFetch fileFetch = new SiteFileFetch(bean); ykAZP[^'
fileFetch.start(); F|mppY'<J
} Y:f"Zx
catch(Exception e){e.printStackTrace ();} u^2)oL
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>6yA+?[:
} i7rO5<
p;#@#>h
\ @XvEx%
public static void main(String[] args) B^|^hZZ>
{ vndD#/lXq
new TestMethod(); @fz0-vT,
} .J=<E
} LtrE;+%2oz
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