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)); 5Y5N
} Zb2.o5#}
for(int i=0;i<nEndPos.length-1;i++) ?V})2wwP
{ \; zix(N[5
nEndPos = nStartPos[i+1]; `llSHsIkXb
} !I Byv%m&\
nEndPos[nEndPos.length-1] = nFileLength; cKt8e^P
} 4K!@9+Mz
} cC$E"m
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b@[\+P] "
//启动子线程 ?r R, h{~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H?j}!JzAC
for(int i=0;i<nStartPos.length;i++) -l$-$,M`#
{ I_'0!@Nn7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jxZd =%7Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }#E~XlX^
nStartPos,nEndPos,i); %loe8yt
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $BDl
fileSplitterFetch.start(); /pz(s+4=
} yV5AVMo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), L)_L#]Yy
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); sX]ru^F3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C6c]M@6
nEndPos = " + nFileLength); =)2!qoE
// fileSplitterFetch[nPos.length-1].start(); ea!Znld]
P26YJMJ'
,IG?(CK|
//等待子线程结束 ;%Zn)etu
//int count = 0; "3VMjF\
//是否结束while循环 1{bsh?zd
boolean breakWhile = false; lHSuT2)x;
fg8U*7
#VM-\02o
while(!bStop) %I;iP|/
{ /-1 F9
write_nPos(); a\v@^4
Utility.sleep(500); G8F43!<
breakWhile = true; TYgn X
~f]I0FK
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for(int i=0;i<nStartPos.length;i++) M2y"M,k4
{ =#{i;CC%
if(!fileSplitterFetch.bDownOver) *M()z.N
{ b+mh9q'5E
breakWhile = false; QP4`r#,
break; IF.6sJg:
} F anA~
} S-)%#
if(breakWhile) \S"YLRn"
break; 9h 0^_|"
( O/+.qb
`xd{0EvF
//count++; hh"=|c
//if(count>4) (Y?"L_pC
// siteStop(); [<7Vv_\Q
} dtUt2r)6L;
k{j (Gb2sp
D3-H!TFpDb
System.err.println("文件下载结束！"); |DMa2}%
} j%OnLTZ
catch(Exception e){e.printStackTrace ();} lBnG!!VrWa
} N}j^55M_]
`Hq)g1a7q
}mSfg
//获得文件长度 3QzHQU
public long getFileSize() =o+))R4
{ 6z80Y*|eJ
int nFileLength = -1; mu =H&JC
try{ fF} NPl
URL url = new URL(siteInfoBean.getSSiteURL()); aqAWaO
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (@1*-4l
httpConnection.setRequestProperty("User-Agent","NetFox"); hh>mX6A
ckPI^0A!
f")*I
int responseCode=httpConnection.getResponseCode(); J|2OmbJe
if(responseCode>=400) QGV~Y+
{ ?$LKn2C
processErrorCode(responseCode); b ZEyP W
return -2; //-2 represent access is error !{L`Zd;C>w
} +yd(t}H@
BKQI|i
-wjvD8fL
String sHeader; `CQMvX{
Wg2Y`2@t
l4s_9
for(int i=1;;i++) tJ,x>s?Y
{ ?4i:$.A Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4#BoS9d2I<
//Utility.log(in.readLine()); )R`w{V
sHeader=httpConnection.getHeaderFieldKey(i); X#*|_(^
if(sHeader!=null) ;n,@[v
{ @dj2#
if(sHeader.equals("Content-Length")) P7i G,i
{ px1{=~V/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "' hc)58y
break; |_J[n!~f7
} idr,s\$>
} `Vqpo/
else aGYF\7
break; 51k^?5cO
} F!;0eS"xp
} A+lP]Oy0S
catch(IOException e){e.printStackTrace ();} Qpc+1{BQ
catch(Exception e){e.printStackTrace ();} &S"ojbb
EK6fd#J?1
:}Tw+S5
Utility.log(nFileLength); d= -/'_'
$6XCHVx
N3Jfp3_b@
return nFileLength; zp2IpYQ,3
} !`G7X
(&G4@Vd
^"h`U'YC
//保存下载信息（文件指针位置） tGs=08`
private void write_nPos() \=yx~c_$L
{ \HB4ikl
try{ 1cyX9X
output = new DataOutputStream(new FileOutputStream(tmpFile)); /M-%]sayj
output.writeInt(nStartPos.length); D+.h*{gD
for(int i=0;i<nStartPos.length;i++) a N|MBX;
{ uwl;(zwh_
// output.writeLong(nPos); G2%%$7Jj
output.writeLong(fileSplitterFetch.nStartPos); dw60m,m
output.writeLong(fileSplitterFetch.nEndPos); U'st\Dt
} F-k3F80=
output.close(); 1YA_`_@w
} O0{M3-
catch(IOException e){e.printStackTrace ();} ?[\(i)]
catch(Exception e){e.printStackTrace ();} M<,E[2op
} D 5qCn^R
k@eU #c5c
s wdW70
//读取保存的下载信息（文件指针位置） ,?+rM ;
private void read_nPos() %/:{x()G
{ Z%Nl<i
try{ L!7*U.+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); lbv9 kk[
int nCount = input.readInt(); Y)>GwFK$
nStartPos = new long[nCount]; l("Dw8H
nEndPos = new long[nCount]; eyZ /%4'q
for(int i=0;i<nStartPos.length;i++) 7mSVL\\^
{ Elt=/,v`!
nStartPos = input.readLong(); N4%q-fi
nEndPos = input.readLong(); ~h] <E
} RpE69:~PV
input.close(); dFF[2
} Nkt(1?:-'
catch(IOException e){e.printStackTrace ();} Eg?6$[U`8<
catch(Exception e){e.printStackTrace ();} W^W^5-'"D,
} J3fcnI
qJj;3{X2
t]Xdzy
private void processErrorCode(int nErrorCode) wwS{V
{ Z,Z34:-
System.err.println("Error Code : " + nErrorCode); DYU+?[J
} n\}!'>d'
t)LD-%F
b]s*z<|%
//停止文件下载 .N99=%[}h
public void siteStop() cbl2D5s+i]
{ "SyAOOZ
bStop = true; cjU*
for(int i=0;i<nStartPos.length;i++) c<j2wKz
fileSplitterFetch.splitterStop(); DKCPi0
\FSkI0
euS"C*
} (xJ6: u
} aD,sx#g0
//负责部分文件的抓取 yVm~5Y&Z
**FileSplitterFetch.java ?9_<LE q
*/ +Eh1>m
package NetFox; 4!<8Dd
"z\T$/
}+0{opY4R
import java.io.*; BF2,E<^A
import java.net.*; Dx =ms^oN5
7z"xjA
{T Z7>k
public class FileSplitterFetch extends Thread { V+X>t7.Q
2JZf@x+}
;}{%|UAsx
String sURL; //File URL V?v,q'? $
long nStartPos; //File Snippet Start Position C`3}7qi|C
long nEndPos; //File Snippet End Position 2/qP:3)
int nThreadID; //Thread's ID "#2z 'J
boolean bDownOver = false; //Downing is over S*6P=O*
boolean bStop = false; //Stop identical 1Tf"<Dp
FileAccessI fileAccessI = null; //File Access interface pGz-5afL
\~1M\gZP
kC"<4U
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Uu{I4ls6B
{ 6)m}e?D>
this.sURL = sURL; t5#IiPp
this.nStartPos = nStart; o`HZS|>K*
this.nEndPos = nEnd; OS6 l*S('
nThreadID = id; 8*3<Erv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l [?o du4
} ]:JoGGE a0
]S4kWq{Y
a|`Pg1j#
public void run() KFdTw{GlJ7
{ :3$WY<
while(nStartPos < nEndPos && !bStop) .oYUA}
{ Fd-PjW/E8
v2:A 4Pd:+
Y@N}XH<4R
try{ (7q!Z!2
URL url = new URL(sURL); ;wIpche
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); y]aV7 `]
httpConnection.setRequestProperty("User-Agent","NetFox"); 2&O!<C j
String sProperty = "bytes="+nStartPos+"-"; &a%|L=FY
httpConnection.setRequestProperty("RANGE",sProperty); @Hj5ZJ 3
Utility.log(sProperty); 1+RG@Cp
LY[XPV]t
4df)?/
InputStream input = httpConnection.getInputStream(); =vMFCp;mv
//logResponseHead(httpConnection); EAU6z(X$
7y:%^sl
[f}YXQ0N)
byte[] b = new byte[1024]; mOr>*uR
int nRead; Cfu]umZLn
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tgH@|Kg
{ y^tuybpZY<
nStartPos += fileAccessI.write(b,0,nRead); Qx|m{1~-
//if(nThreadID == 1) <Yu}7klJE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); twU^ewO&
} W}bed],l
Vo<V!G{
tvynl;Y/
Utility.log("Thread " + nThreadID + " is over!"); b[Sd$ACd
bDownOver = true; j2SJ4tB /
//nPos = fileAccessI.write (b,0,nRead); * F%Wf
} EV| 6._Z(D
catch(Exception e){e.printStackTrace ();} b;#3X)
} wl #Bv,xf
} 5G cdz
e5_a.c
U7O~ch[,
//打印回应的头信息 Bs(\e^}
public void logResponseHead(HttpURLConnection con) m!5P5U x
{ | ?3\xw
for(int i=1;;i++) Mfe/(tlI
{ Ehu^_HZ
String header=con.getHeaderFieldKey(i); nIJ2*QJ
if(header!=null) bB@1tp0+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :}}5TJwG
Utility.log(header+" : "+con.getHeaderField(header)); ya3A^&:
else bmVksi2b
break; ,\q9>cZ!
} 7{=/rbZT?
} ED&>~~k)
6/Y3#d
`z%f@/:fG
public void splitterStop() 4Tgy2[D?q
{ 2{Nv&ZX?
bStop = true; %1ZJi}~
} yEyx.Mh.Af
13wO6tS k
[ZU6z?Pf
} ]3]I`e{
=mxG[zDtQ
XQ]noaU
/* &^Q-:Kxs8
**FileAccess.java >%5Ld`c:SD
*//文件访问(定位，写) NpqMdd
package NetFox; B-PN +P2
import java.io.*; -/rP0h5#
/]m5HW(P7K
6r{NW9y'
public class FileAccessI implements Serializable{ ;rZR9fR
OjTb2[Q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rpH ,c[D
RandomAccessFile oSavedFile; esU9
long nPos; ;+] mcgN!
(CFm6p'RZ
ZN#mu]jC?
public FileAccessI() throws IOException "1|n]0BF
{ 2\80S[f
this("",0); }A,9`
} ekC 1wN l
AL@8v=
QG {KEj2V
public FileAccessI(String sName,long nPos) throws IOException \Fg%V>
{ 9`
oSavedFile = new RandomAccessFile(sName,"rw"); `~0)}K.F
this.nPos = nPos; a(RTb<
oSavedFile.seek(nPos); Hc^q_{}"
} l =~EweuM
=REMSej
4FUY1p
public synchronized int write(byte[] b,int nStart,int nLen) }-QFMPXhG
{ I^S gWC
int n = -1; 0'q&7 MV
try{ E{x<P0 ;
oSavedFile.write(b,nStart,nLen); `L# pN5
n = nLen; KBJ%$OQV
} ScOiOz:Ha
catch(IOException e) v,bCj6
{ 6HocF/Ye
e.printStackTrace (); Gy 0 m
} LkYcAY$w
|j:"n3~6
}2c)UQD8
return n; WjLy7&
} :"QR;O@
2$ m#)*\
%f3qCN
} \Gm$hTvB&
d[K71
&h^E_]P
/* }#%3y&7M7
**SiteInfoBean.java A$d)xq-]K
*/ &%eWCe++
package NetFox; Sd[%$)scC
tNpBRk(}
{jdtNtw
public class SiteInfoBean { |Z6M?n
?RW7TWf
A#NJ8_
private String sSiteURL; //Site's URL _mSDz=!Z3
private String sFilePath; //Saved File's Path /bm2v;
private String sFileName; //Saved File's Name \tR](, /
private int nSplitter; //Count of Splited Downloading File h[eCi
C7PVJnY0
-_@zyF<G
public SiteInfoBean() iM \3~3'
{//nSplitter的缺省值为5 >Sc)?[H
//default value of nSplitter is 5 _[%2QwAUj*
this("","","",5); J>D+/[mFt
} ctg U
S7oPdzcU-
}-`N^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) rgq~lZ.U4K
{ Qc4r?7S<
sSiteURL= sURL; @QOlo-u
sFilePath = sPath; 1f}YKT
sFileName = sName; ZVu_E.4.
this.nSplitter = nSpiltter; QjT$.pUd
FR*CiaD1
&~4;HjS
} 2Xw=kwu
RBOb/.$
pg<m0g@W*;
public String getSSiteURL() D;?cf+6$
{ 0FN;^hP5|
return sSiteURL; tL#~U2K
} _\"2Mdk`]
6=pE5UfT
OdKfU^
public void setSSiteURL(String value) S7!+8$2mc_
{ /H (55^EMZ
sSiteURL = value; I1f4u6\*X
} }xx"
,5*Z<[*
)wZ;}O
public String getSFilePath() a7Mn/ i.
{ "FD`1
return sFilePath; \p4>onGI
} =Ff _)k
ZYS`M?Au
bm>N~DC
public void setSFilePath(String value) EKgY
{ r!+..c
sFilePath = value; QT8GP?F
} C4[)yJ
c/6
;{L~|q J
public String getSFileName() lwSZpS
{ }yzCq+
return sFileName; QG1+*J76b@
} !l(D0 C
s!IX3rz
APgjT';P^
public void setSFileName(String value) NZb}n`:
{ "1P[D'HV4|
sFileName = value; AONEUSxJ
} : Iq
A4~-{.w=
|l-~,eRvi5
public int getNSplitter() y:HH@aa)
{ Sj'Iz #
return nSplitter; d6+$[4w
} 2RbK##`vC
WrHY'
L*6R5i>
public void setNSplitter(int nCount) WEaG/)y
{ fEo5j`}
nSplitter = nCount; m{gw:69h
} 8P?p
} BQ:hUF3
!qu/m B
u<['9U
/* $xU)t&Df
**Utility.java En9>onJ
*/ `VrQ?s
package NetFox; O7"16~a
56?RFnZ&j
%f?Z/Wn
public class Utility { fsjCu!
WR"?j9y_q
B"Ma<"HU
public Utility() ey]WoUZ
{ <*Gd0 v%
a$=He
`nCVO;B
} O#@G .~n?
:Ahw{z`H#
//线程睡眠 9u;/l#?@T
public static void sleep(int nSecond) ^O3i)GO
{ p:NIRs
try{ GYt|[GC
Thread.sleep(nSecond); )61X,z
} / q| o
catch(Exception e) *B)J(^M!q
{ ^)E# c
e.printStackTrace (); HfPu~P
} ^]NFr*'!
} Bwc_N.w?3
_Rb>py
//日志 Xqy9D ZIn
public static void log(String sMsg) ,hOi5,|?L
{ ElA(1o|9I
System.err.println(sMsg); 9vckQCLM
} g)1`A24
sj3[ny;b
#9glGPR(
public static void log(int sMsg) +-!2nk`"a
{ l*w*e.ezQ
System.err.println(sMsg); hLr\;Swyp
} vD^Uod1
} 6)veuA3]
/E-sg, k
&0`i(l4]l
/* #OlPnP2
**TestMethod.java "s.hO0Z
*/ hCb2<_3CR
package NetFox; r4M;]
.*X=JFxl
U1W8f|u
public class TestMethod { :6qt[(<"
] T<#bNK\1
&;naaV_2T
public TestMethod() TT oW>RP#
{ ///xx/weblogic60b2_win.exe %i.Prckrb
try{ fZp3g%u
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <Gna}ALkg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Vb)NWXmyu
SiteFileFetch fileFetch = new SiteFileFetch(bean); aL&nD1f=!-
fileFetch.start(); ,1B`Ve
} jp7cPpk:LG
catch(Exception e){e.printStackTrace ();} l<;~sag
6Nws>(Ij
3T/&T`T+c
} :O7n*lwx
je`Inn<
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public static void main(String[] args) Z7NR%u_|[
{ -zzoz x]S=
new TestMethod(); %NDr5E^cc
} ,h9?o
} _C)\X(;
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