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)); Bmuf[-}QW
} JPL8fX-w
for(int i=0;i<nEndPos.length-1;i++) p%e!&:!
{ ?6.vd]oNO
nEndPos = nStartPos[i+1]; jq(3y|6,
} 1BQTvUAA
nEndPos[nEndPos.length-1] = nFileLength; k+S+: 5
} $@d`Kz;
} m)9N9Ii#)
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//启动子线程 Y W_E,A>h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; K;;Q*NN-
for(int i=0;i<nStartPos.length;i++) `HU`=a&d
{ fVv#|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Frn#?n)S9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ):?ype>
nStartPos,nEndPos,i); vco/h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =Run
fileSplitterFetch.start(); =MO2M~e!
} LB%_FT5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), awuUaE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); a%f{mP$m
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {LTb-CB
nEndPos = " + nFileLength); Us.yKAHPV
// fileSplitterFetch[nPos.length-1].start(); :Bp{yUgi@
D4'"GaCv
>U~.I2sz
//等待子线程结束 Z:aDKAboU
//int count = 0; e3YZ-w^W~h
//是否结束while循环 I2("p.+R
boolean breakWhile = false; b6_*ljM
f|Kd{ $VO
lqAU5K{wQ
while(!bStop) >bxT_qEm
{ 8h9t8?
write_nPos(); *JGm
Utility.sleep(500); *2crhI*@>
breakWhile = true; VBR@f<2L
L5%~H?K(
)/2* <jr
for(int i=0;i<nStartPos.length;i++) %*OKhrM
{ ? Ldw\
if(!fileSplitterFetch.bDownOver) !;lA+O-t
{ &w:"e'FG`
breakWhile = false; _6THyj$f
break; cRz7.9-<
} X obiF
} 7M}T^LC
if(breakWhile) i:OD)l
break; hbR;zV|US
e.G&hJr
s2g}IZfo
//count++; ^mFuZ~g;?
//if(count>4) UY j
// siteStop(); iKV;>gF,)v
} $;7?w-.
T2Cdw\
O<S*bN>BF
System.err.println("文件下载结束！"); eJE?H]
} /7|u2!#Ui
catch(Exception e){e.printStackTrace ();} BMU~1[r
} nlHH}K
@z$V(}(O^
n?&G>`u*
//获得文件长度 1W8[ RET
public long getFileSize() hnL"f[p@gC
{ ujB:G0'r
int nFileLength = -1; xBG&ZM4"^f
try{ W5$jIQ}Bw
URL url = new URL(siteInfoBean.getSSiteURL()); M]jzbJ3Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ko im@B
httpConnection.setRequestProperty("User-Agent","NetFox"); s7O?)f f
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5'\/gvxIC
int responseCode=httpConnection.getResponseCode(); O-wR48Q
if(responseCode>=400) /+2^xEIjE
{ =w".B[r
processErrorCode(responseCode); E8jdQS|i
return -2; //-2 represent access is error zdyS"H}
} "<3PyW?zt
-}2q-
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String sHeader; P`[6IS#\S
; z:}OD
3RscuD&
for(int i=1;;i++) 0Z2![n
{ A[XEbfDO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Il'+^u_ <
//Utility.log(in.readLine()); $"J+3mO
sHeader=httpConnection.getHeaderFieldKey(i); y M , hF
if(sHeader!=null) ],>Z'W
{ oQ8W0`bZa
if(sHeader.equals("Content-Length")) ..'^1IOA
{ n0@e%=H)I
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); nEQw6q~je
break; }_3<Q\j
} GpN tvo~
} LEc%BQx
else 65=i`!f
break; p[hA?dXn
} 1`5d~>fV
} h<6@&yzp
catch(IOException e){e.printStackTrace ();} E$4\Yc)(AL
catch(Exception e){e.printStackTrace ();} 50l=B]M
fph*|T&R
@4T+0&OI10
Utility.log(nFileLength); $}aLFb
zYYc#N/
puL1A?Y8UM
return nFileLength; x76<u:
} i~n>dc YW
<{9E.6G`n
p/cVQ
//保存下载信息（文件指针位置） QlSZr[^v
private void write_nPos() ]5YG*sD4
{ /(E)|*~6
try{ 7zgU>$i
output = new DataOutputStream(new FileOutputStream(tmpFile)); Pd%o6~_*
output.writeInt(nStartPos.length); B<H5WI
for(int i=0;i<nStartPos.length;i++) hCc_+/j|
{ /"~CWNa
// output.writeLong(nPos); ts{Tk5+
output.writeLong(fileSplitterFetch.nStartPos); ,N<xyx.
output.writeLong(fileSplitterFetch.nEndPos); i0L)hkV
} 31 QT
output.close(); 1$q SbQ
} ]GJIrtS4
catch(IOException e){e.printStackTrace ();} S)n~^q
catch(Exception e){e.printStackTrace ();} ^$6EO)<
} pI( OI>~3
Xi6XV3G
wX<)Fj'
//读取保存的下载信息（文件指针位置） p3\F1](Z
private void read_nPos() =sG C
{ :jT1=PfL
try{ 3EI$tP@4
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Ih{(d O;
int nCount = input.readInt(); 3(}W=oI
nStartPos = new long[nCount]; J3oH^
nEndPos = new long[nCount]; 3*/y<Z'H
for(int i=0;i<nStartPos.length;i++) @@# ^G8+l
{ |/Ggsfmby
nStartPos = input.readLong(); "/S-+Ufn
nEndPos = input.readLong(); 2x"&8Bg3
} dTB^6>H
input.close(); G9 ;X=c
} O< v0{z09*
catch(IOException e){e.printStackTrace ();} ry*b"SO
catch(Exception e){e.printStackTrace ();} (ye1t96
} Y#=0C*FS
O8wR#(/
N41)?-7F
private void processErrorCode(int nErrorCode) ]L"jt8E
{ N8@Fj!Zi
System.err.println("Error Code : " + nErrorCode); X"z^4?Aj+
} Q=)$
MXh0a@*]
`%ZM(9T
//停止文件下载 D. fPHq
public void siteStop() pi*cO
{ _rdEur C6
bStop = true; I%ivY
for(int i=0;i<nStartPos.length;i++) \xlelsmB*
fileSplitterFetch.splitterStop(); g=0`^APql
)>QpR8 G-
}R=n!Y$F
} v,I4ozDx
} H9?(5
//负责部分文件的抓取 _D1Uc|
**FileSplitterFetch.java UMILAoR
*/ &G\Vn,1v
package NetFox; 0Dv r:]R
}^+E S^~
F0t-b%w,
import java.io.*; 5Tag-+
import java.net.*; -GJ~xcf0
}`ox;Q
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public class FileSplitterFetch extends Thread { [3lAKI
Sg
4 3V{q
String sURL; //File URL |J-Osi
long nStartPos; //File Snippet Start Position F$.h+v
long nEndPos; //File Snippet End Position NX%"_W/W
int nThreadID; //Thread's ID _JNSl2
boolean bDownOver = false; //Downing is over 8JYU1Ew
boolean bStop = false; //Stop identical 6|:K1bI)
FileAccessI fileAccessI = null; //File Access interface o9\J vJk
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hGh91c;4
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]dIcW9a
{ Nk?eVJ)
this.sURL = sURL; S9RH&/^H
this.nStartPos = nStart; !xcLJ5^W
this.nEndPos = nEnd; "`g5iUHqUl
nThreadID = id; ^%ZbjJ7|j
fileAccessI = new FileAccessI(sName,nStartPos);//定位 AK$&'t+$}7
} Yw=7(}
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public void run() .JCd:'-
{ _Ns/#Xe/
while(nStartPos < nEndPos && !bStop) 9UDanj P
{ ,/2&HZd
W%@r
Z<D8{&AjS
try{ tE'^O< K
URL url = new URL(sURL); O]_a$U*6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); OFe-e(c1
httpConnection.setRequestProperty("User-Agent","NetFox"); XM1; >#kz
String sProperty = "bytes="+nStartPos+"-"; \MqOHM.[
httpConnection.setRequestProperty("RANGE",sProperty); y'L7o V?L9
Utility.log(sProperty); QNbV=*F?
cYmgJBG
w1Txz4JqB
InputStream input = httpConnection.getInputStream(); 6 &Lr/J76
//logResponseHead(httpConnection); !,lk>j.V
0:I[;Qt
"w&IO}j;=
byte[] b = new byte[1024]; d!{]CZ"@
int nRead; CKI.\o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~Uw;6VXV1
{ t =V| '
nStartPos += fileAccessI.write(b,0,nRead); HK NT. a
//if(nThreadID == 1) bog3=Ig-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j+9;Rvt2
} wKU9I[]
w**~k]In
p0rmcP1Ln
Utility.log("Thread " + nThreadID + " is over!"); j)ME%17
bDownOver = true; }1 ,\*)5
//nPos = fileAccessI.write (b,0,nRead); n&l(aRoyx
} sZx`u+
catch(Exception e){e.printStackTrace ();} Gg e X
} Ptm=c6H('
} t!-\:8n
iC{(vL0P+
5Q;Q
//打印回应的头信息 2##;[
public void logResponseHead(HttpURLConnection con) %2wr%*h
{ W_L*S4 ~
for(int i=1;;i++) 9>ajhFyOhX
{ e%s1D
String header=con.getHeaderFieldKey(i); )SZzA'
if(header!=null) 8WE@ X)e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r]@T9\9
Utility.log(header+" : "+con.getHeaderField(header)); $Qz<:?D
else -Ew>3Q
break; Z`_x|cU?J
} wBDHhXi0
} $DXO7;#
E{0e5.{
qV9}N-sS
public void splitterStop() Pbd[gKX_
{ 3! #|hI>f
bStop = true; yAAV,?:o[
} r?itd)WC<X
jzJQ/ZFS
Zs(BViTb|
} Nw9@E R
3?K+wg s
_&~l,%)&
/* 0BNH~,0u
**FileAccess.java tm/=Oc1p
*//文件访问(定位，写) F?$Vx)HI
package NetFox; Fv7]1EO.
import java.io.*; k-H6c
fF(AvMsO
[O<F`u"a
public class FileAccessI implements Serializable{ )!kt9lK
fP:]s@$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 o{>4PZ}=g
RandomAccessFile oSavedFile; whYk"N
long nPos; A@Q6}ESD
LtH j
"b402"&
public FileAccessI() throws IOException Auc&dpW
{ l9C `:g
this("",0); :-O$rm
} KTt+}-vP^
Oe x
J90:c@O"w
public FileAccessI(String sName,long nPos) throws IOException k;jl3GV
{ 2Y%7.YX"
oSavedFile = new RandomAccessFile(sName,"rw"); sZ~03QvkT
this.nPos = nPos; *+zFsu4l
oSavedFile.seek(nPos); c]Gs{V]\
} %19~9Tw
!yT=*Cj4
I{0cnq/
public synchronized int write(byte[] b,int nStart,int nLen) tvf5b8(Y-
{ ?A;RTM
int n = -1; X $V_
try{ `k>C%6FG$#
oSavedFile.write(b,nStart,nLen); @54$IhhT~
n = nLen; )5n0P Zi
} 8G3 Z,8P4(
catch(IOException e) j94~cYV
{ 0C.5Qx
e.printStackTrace (); :-#7j} R&
} R<_VWPlj
[TQYu:e
IP$eJL[&D"
return n; `q\F C[W
} dl[%C6
?*$uj(
Y'jgp Vt
} 5x|$q kI
wl%ysM|x
O7_y QQAA
/* "=K3sk
**SiteInfoBean.java w)* H&8h@
*/ 4"Qb^y
package NetFox; fd #QCs
FWU>WHX
@`+\vmfD
public class SiteInfoBean { Tc!n@!RA|
_VjaTw8iM
Ek_&E7
private String sSiteURL; //Site's URL KPDJ$,:
private String sFilePath; //Saved File's Path 6T+ym9
private String sFileName; //Saved File's Name %).I&)i
private int nSplitter; //Count of Splited Downloading File H"A@Q.'
o3\^9-jmp
= 03G~7B>
public SiteInfoBean() 8@+<W%+th
{//nSplitter的缺省值为5 9015PEO
//default value of nSplitter is 5 !-n*]C
this("","","",5); %-fS:~$
} RTvOaZ
-K$ugDi
BMQ4i&kF|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Nxl#]
{ OGLA1}k4
sSiteURL= sURL; pYm#iz
sFilePath = sPath; THX% z `
sFileName = sName; ^8bc<c:P
this.nSplitter = nSpiltter; nj00g>:>
etX(~"gG_
6 <`e]PT
} 6C"zBJcGc
N"RPCd_
>ySO.S
public String getSSiteURL() _<2{8>EVf
{ \(=xc2
return sSiteURL; DWx;cP8[
} *kZH~]
k^ fW/
3?`TEw~'
public void setSSiteURL(String value) G#f3 WpD
{ W`oyDg,D
sSiteURL = value; = =Q*|L-g
} })kx#_o]'d
1#;^Z3
xT* 3QwK
public String getSFilePath() eHGx00:
{ FYu30
return sFilePath; `-cw[@uD
} k#~oagW_Gw
;gu4~LQw
J(~1mIJjC
public void setSFilePath(String value) 'r_Fi5[q
{ [g:cG
sFilePath = value; LfU? 1:Du
} }M"])B I
b KIL@AI
-vc$I=b;
public String getSFileName() ,CPAS}kS
{ 91yYR*
return sFileName; 6@47%%,}
} E+e),qsbO
_\,lv \u
v$JW7CKA
public void setSFileName(String value) i|,}y`C#
{ ./.aLTh
sFileName = value; {(asy}a9K
} *}Gys/\!S
XhWo~zh"
U1fqs{>
public int getNSplitter() 2ve<1+V_
{ r| \""
return nSplitter; *wd=&Z^19
} `(P71T
XDyo=A]
=WZ9|e
public void setNSplitter(int nCount) `)KGajB
{ N'l2$8
nSplitter = nCount; m]Qs BK
} PQYJnx}
} :9x]5;ma
rFm?Bu
7PUy`H,&
/* h -091N
**Utility.java ` l'QAIo
*/ g`.H)36
package NetFox; xb9^WvV
nox-)e
fk1d iB
public class Utility { Z0'LD<
;Oq>c=9%
0jxXUWO
public Utility() 0(Z:QqpU$
{ u}_x
KIWHn_ :
pX!T; Re;
} 'IVC!uL,%
60e{]}Z
//线程睡眠 x5;D'Y t"|
public static void sleep(int nSecond) [ z/G
{ M_cm,|FF
try{ /!6 VP |
Thread.sleep(nSecond); nG?Z* n
} l>BM}hS
catch(Exception e) 4R8Qn^
{ 83#<Yxk~
e.printStackTrace (); T-7(3#&
} "qZTgCOY2
} R `ob;>[Q
Qn-nO_JL
//日志 4W E)2vkS
public static void log(String sMsg) w_~tY*IwB
{ %X%f0J
System.err.println(sMsg); )MoHY
} Gb"kl.j
e~,+rM
/%t`0pi
public static void log(int sMsg) f/0k,~,*
{ h:FN&E c}
System.err.println(sMsg); d}Y#l}!E6
} gdyWuOxa|
} ka(3ONbG
zNn
P~x4h{~Gd
/* jSdC1,wR
**TestMethod.java ajkpU.6E:
*/ ]S@DVXH
package NetFox; \]S)PDqR
=t~]@?]1D
dEX67rUj;
public class TestMethod { i`}9VaUG
W%9~'pXgB
@.G;dL.f{
public TestMethod() ]]_c3LJ2`
{ ///xx/weblogic60b2_win.exe W~l.feW$i
try{ mr]~(]B?r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); GFnwj<V+{
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); lD# yXLaC\
SiteFileFetch fileFetch = new SiteFileFetch(bean); u,`V%J?vW
fileFetch.start(); R.GDCGAL
} QMDkkNK
catch(Exception e){e.printStackTrace ();} 9c0
^0I"
Qdc)S>gp
} ;vk>k0S
onv0gb/J
&*Kk> 4
public static void main(String[] args) yVpru8+eD
{ VjeF3pmBa
new TestMethod(); T=g2gmo9
} 7o7FW=^
} 8ddBQfCY
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