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)); vI4%d,
} 9UB??049z
for(int i=0;i<nEndPos.length-1;i++) 2&suo!ig
{ {_": /A
nEndPos = nStartPos[i+1]; <XU8a:w'T
} h5<T.vV
nEndPos[nEndPos.length-1] = nFileLength; h 3eGq:!9
} Xqc'R5Cw
} 0c%@e2(N
aB/{ %%o
WNCM|VUl
//启动子线程 3we.*\2$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jq7vOr-_g
for(int i=0;i<nStartPos.length;i++) (N&k}CO]W
{ ^)(G(=-Rf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u Eu6f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n$nne6|O
nStartPos,nEndPos,i); TJeou#=/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H9.oVF^~
fileSplitterFetch.start(); S(@*3]!q
} _G_ &Me0
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), kyp U&F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fQ2!sV
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", GZxglU,3T
nEndPos = " + nFileLength); ;a#}fX
// fileSplitterFetch[nPos.length-1].start(); Sn_z
wjN`EF5$}&
u>JqFw1
//等待子线程结束 6RR4L^(m
//int count = 0; 4`?sE*P@`
//是否结束while循环 ~)WfJ
boolean breakWhile = false; =d:R/Z%,
O6M}W_
=U)n`#6_j2
while(!bStop) IwZZewb-a
{ >#Grf)@"6
write_nPos(); azz#@f1
Utility.sleep(500); D}=/w+
breakWhile = true; |JirBz
DQL06`pX/
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for(int i=0;i<nStartPos.length;i++) Dx p>
{ }rFsU\]:q
if(!fileSplitterFetch.bDownOver) w0q?\qEX
{ KZ367&>b7
breakWhile = false; I{i:B
break; yfRUTG
} (cPeee%Q
} :)^# xE(
if(breakWhile) &>+I7Ts]
break; 6qz!M
+An![1N,
O2V6UX@&<w
//count++; EF*oPn0|
//if(count>4) w>/pQ6=OFR
// siteStop(); Wwa41z
} t?3{s\z8+
muqfSF
]4LT#
System.err.println("文件下载结束！"); Yc. ~qmG/z
} \N'hbT=
catch(Exception e){e.printStackTrace ();} R{2GQB
} "-~D!{rS
5~<a>>
%l9WZ*yZ`2
//获得文件长度 Xr
public long getFileSize() Z L6~Eut
{ 5JXzfc9rL
int nFileLength = -1; u"Hd55"&
try{ / y":/"h
URL url = new URL(siteInfoBean.getSSiteURL()); ]$XBd{\D{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); T_YMM'`
httpConnection.setRequestProperty("User-Agent","NetFox"); '6dD^0dZ
xv(xweV+d
q;Ar&VrlNq
int responseCode=httpConnection.getResponseCode(); '.}6]l
if(responseCode>=400) yNb#Ia
{ utFcFdX
processErrorCode(responseCode); {Q#Fen ;y|
return -2; //-2 represent access is error iuH8g
} 32)&;
\$$b",2 h
F$sF 'cw
String sHeader; Nd]%ati?
Qzs\|KS
vV&AG1_Mv
for(int i=1;;i++) h[[/p {z
{ R~x;X3
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x]mye
//Utility.log(in.readLine()); -x3tx7%
sHeader=httpConnection.getHeaderFieldKey(i); "p6:ekw
if(sHeader!=null) #qiGOpTF.
{ RT_Pd\(qD
if(sHeader.equals("Content-Length")) tnKpn-LPA
{ 0Tn|Q9R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,h5-rw'
break; ]C!Y~
} 8g2-8pa{
} i\DHIzGp[
else ]y)R C-N
break; ]<o.aMdV
} 7zJh;f/
} ^V0{Ew/x
catch(IOException e){e.printStackTrace ();} c5mhl;+'
catch(Exception e){e.printStackTrace ();} ;'WzfJ!q
-Uhl9 =
q!9v}R3(
Utility.log(nFileLength); U d=gdsL
3 DO$^JJ.
4 L~;>]7
return nFileLength; M#8Ao4 T
} X~Rk ,d3
!=q:>}g
BF1O|Q|d6
//保存下载信息（文件指针位置） |<+|Du1
private void write_nPos() #G4~]Qml
{ -XDP-Trk
try{ u`H@Q&(^wa
output = new DataOutputStream(new FileOutputStream(tmpFile)); bTy'5"
output.writeInt(nStartPos.length); 3Mh,NQB
for(int i=0;i<nStartPos.length;i++) /PB3^d>Q2
{ D=I5[t0c4
// output.writeLong(nPos); gQ@Pw4bA
output.writeLong(fileSplitterFetch.nStartPos); 65`'Upu
output.writeLong(fileSplitterFetch.nEndPos); .KwuhmR
} ZjI/zqBm
output.close(); f)s_e
} {p lmFV
catch(IOException e){e.printStackTrace ();} e2=,n6N]c
catch(Exception e){e.printStackTrace ();} -R8!"~o
} pg& ]F
wor'=byh\
fE7a]REK
//读取保存的下载信息（文件指针位置） v BeU
private void read_nPos() R82Zr@_
{ *O}'2Ht6\
try{ M]/wei"X
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); .V)2Tz
int nCount = input.readInt(); ??e#E[bI
nStartPos = new long[nCount]; OTtanJ?
nEndPos = new long[nCount]; ]JCB^)tM
for(int i=0;i<nStartPos.length;i++) c7TWAG_+
{ 5P t}
nStartPos = input.readLong(); 9{^B Tc
nEndPos = input.readLong(); :7PSZc:xE
} XL&eJ
input.close(); a ~iEps
} 'N5r2JL[w
catch(IOException e){e.printStackTrace ();} t=pkYq5t8
catch(Exception e){e.printStackTrace ();} [m+O0VK$
} d(B;vL@R2V
]!Aze^7;
~JmxW;|_x)
private void processErrorCode(int nErrorCode) \g6 #MNW
{ O@(.ei*HJ!
System.err.println("Error Code : " + nErrorCode); }${ZI
} &=yqWW?
eiSO7cGy
d8q$&(]<
//停止文件下载 \,IDLXqp
public void siteStop() HgBEV
{ yI)fu^
bStop = true; @j8L{FGnN
for(int i=0;i<nStartPos.length;i++) &7kSLat+9{
fileSplitterFetch.splitterStop(); sbiDnRf
rJ~(Xu>,s
Fe2-;o
} d?qO`- ~$
} r-"`Abev
//负责部分文件的抓取 )Jjw}}$}Y
**FileSplitterFetch.java pS)X\Xyw
*/ )mZy>45
package NetFox; 3z. >b
:V1ZeNw
l0bT_?LhK
import java.io.*; cXEy>U|/
import java.net.*; (L
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]8cX#N,M
public class FileSplitterFetch extends Thread { g$+O<a@n
c94PWPU
cFNtY~(b
String sURL; //File URL NU\t3JaR
long nStartPos; //File Snippet Start Position (8X8<>w~
long nEndPos; //File Snippet End Position KNyD}1
int nThreadID; //Thread's ID S5 oHe4#89
boolean bDownOver = false; //Downing is over |;1:$E"
boolean bStop = false; //Stop identical op{(mn
FileAccessI fileAccessI = null; //File Access interface 0QSi\: 1f
{1&,6kJF&9
a}]@o"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException &aht K}u
{ lukRFN>c"
this.sURL = sURL; ~,4Znuin
this.nStartPos = nStart; =]k_Oq-1h
this.nEndPos = nEnd; Rl!WH%;c[X
nThreadID = id; x,*t/nzR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .4)P=*
} 2"K~:Tm#w
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O6 J<Lqgh
public void run() (c7{dYV
{ 8l,hP.
while(nStartPos < nEndPos && !bStop) [GT1,(}. Z
{ p2?+[d
zi 14]FWo
uUB%I 8
try{ 8[p6C Jl)
URL url = new URL(sURL); !8M'ms>s=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'WgwLE_
httpConnection.setRequestProperty("User-Agent","NetFox"); ,>%r|YSJ)
String sProperty = "bytes="+nStartPos+"-"; *iN]#)3>
httpConnection.setRequestProperty("RANGE",sProperty); t/BiZo|zl
Utility.log(sProperty); I:7,CV
-~aEqj#?
6Z}))*3 9
InputStream input = httpConnection.getInputStream(); ~PvzUT-^
//logResponseHead(httpConnection); ]b$,.t5
.Bn2;nO
EqU[mqeF
byte[] b = new byte[1024]; $1 \!Oe[i
int nRead; .F|WQ7Mu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Hx0,kOh)
{ R63d `W
nStartPos += fileAccessI.write(b,0,nRead); Mo=-P2)>lt
//if(nThreadID == 1) a5S/ O;ry
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); B{KD ]
} fYPU'"hzG
2|o$eq3t
vw 2@}#\:
Utility.log("Thread " + nThreadID + " is over!"); 6%y: hLT
bDownOver = true; by[(9+/z$
//nPos = fileAccessI.write (b,0,nRead); k/Ro74f=
} wd0ACF
catch(Exception e){e.printStackTrace ();} WSwmX3rn
} Vjd =F.V+
} '.<"jZ
m$: a|'mS
~q>ilnL"h
//打印回应的头信息 ?P]md9$(+e
public void logResponseHead(HttpURLConnection con) 1mM52q.R4
{ |B.d7@{mM
for(int i=1;;i++) q|2C>{8
{ ,DZLEsFM
String header=con.getHeaderFieldKey(i); bGa":|}F
if(header!=null) E6)mBAE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); VlNzm
Utility.log(header+" : "+con.getHeaderField(header)); u^p[zepW\
else 03;(v%
break; /LzNr0>2
} b)@x@3"O
} I@+<[n2
S5!2%-;<k
%>z}P&Yz
public void splitterStop() gf>5xf{M
{ ;zG|llX
bStop = true; R6Lr]H
} "j>0A Hem
\H(,'w7H
+[DVD
} gk`.8o
ugP R)tDfM
?A>-_B
/* *k$&Hcr$
**FileAccess.java U7=Z.*/62
*//文件访问(定位，写) _Pal)re]U
package NetFox; y_#wR/E)u{
import java.io.*; =ByW`
56dl;Z)
\O~P !`
public class FileAccessI implements Serializable{ Q4*cL5j
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//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 p(>'4#|qy
RandomAccessFile oSavedFile; ^j7pF.j
long nPos; {BU,kjv1g
D bJ(N h
35T7g65;
public FileAccessI() throws IOException EK^2 2vi$
{ us+adS.l&
this("",0); X}Fv*
} V ZGhF!To
q?\D9aT9
HC+R:Dz
public FileAccessI(String sName,long nPos) throws IOException 10^=1@U
{ /[M~##%:
oSavedFile = new RandomAccessFile(sName,"rw"); Rz]bCiD3 B
this.nPos = nPos; -9EbU7>!
oSavedFile.seek(nPos); *<1m 2t>.
} UHWunI S
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ZW"J]"A
public synchronized int write(byte[] b,int nStart,int nLen) NKws;/u
{ ImVe71mh
int n = -1; ^;d;b<
try{ /_8V+@im
oSavedFile.write(b,nStart,nLen); G39t'^ZK*#
n = nLen; v\vn}/>*d
} 8iRQPV-"_
catch(IOException e) fkM4u<R^
{ Tj:F Qnx
e.printStackTrace (); vvCGzOv
} JAK*HA
" B1' K8
[cq>QMW
return n; W2^R$"U
} "cx" d:
m" GrpE3
Y/gCtSF
} 2S3F]fG0
B!0[LlF+
zFIbCv8
/* (WC<XKf
**SiteInfoBean.java M-_)CR
*/ M=%p$\x
package NetFox; 6._):[_2
1mqFnVkf&+
b,wO^07-3^
public class SiteInfoBean { [B Al
u CXd% CzE
:>=,sLfJ
private String sSiteURL; //Site's URL gTT-7
private String sFilePath; //Saved File's Path 53A=Ogk8S
private String sFileName; //Saved File's Name (,>`\\
private int nSplitter; //Count of Splited Downloading File bc-"If Z&
_"n4SXhq
|Cm}%sgR\0
public SiteInfoBean() 4p]Y`];U
{//nSplitter的缺省值为5 %{Gqhb=u\
//default value of nSplitter is 5 5"+* c@L
this("","","",5); a%kj)ah
} !jm a --
s*;~CH-[
UOyP6ej
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) U4gZW]F
{ `#hy'S:e
sSiteURL= sURL; 2mRso.Ah
sFilePath = sPath; XB?!V|bno
sFileName = sName; KE_Ze\P
this.nSplitter = nSpiltter; pR$c<p
\hz)oC
U1Oq"Ij~
} |kn}iA@72p
Z(s} #-
.s+e hZ
public String getSSiteURL() Cfi5r|S
{ u[% #/
return sSiteURL; j2z$kw%
} wBf bpoE7
Tb[GZ,/%;
*m7e>]-
public void setSSiteURL(String value) A/MOY@%G
{ tU(6%zvR
sSiteURL = value; @U}UCG7+
} ny}?+&K
\l`;]cA
WrV|<%EQh
public String getSFilePath() )S]c'}^
{ XH/|jE.9^|
return sFilePath; tC;D4i
} |D\ ukml
,?}TSJKC
4P.ry|2
public void setSFilePath(String value) Sdn] f4
{ ."2V:;;
sFilePath = value; .]" o-(gB
} )}EwEM
`hbM2cM
N7[~Y2i
public String getSFileName() &CS=*)>$
{ \"Np'$4eu
return sFileName; P?I"y,_p
} XjV7Ew^7
- na]P3 s
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public void setSFileName(String value) ALG +
{ }"szL=s
sFileName = value; ,HkJ.6KF
} i}Y:o}
_C##U;e!
, vR4x:W
public int getNSplitter() }\9qN!ol
{ Q5Wb)
return nSplitter; ]UNmhF!W>u
} 2Bx\nLf/ K
Q<M>+U;t
Dd*C?6
public void setNSplitter(int nCount) x[_+U4-/
{ Ft07>E$/Q^
nSplitter = nCount; 0g1uM:;
} ]`lTkh
} O)hNHIF
iM\W"OUl[
RW3&]l=
/* s}5;)>3~@
**Utility.java 0s(G*D2%6
*/ 8garRB{
package NetFox; ~;MRQE
lwV#j}G
f>Ge Em~
public class Utility { bkV_ ^8
^JH 4: h
rx%lL
public Utility() AH;h#dT
{ PJ);d>tz
V ]Z{0
gI[xOK#
} q$\KE4v"
7r:!HmRl
//线程睡眠 Zb@PwH4
public static void sleep(int nSecond) Mq-;sPsFP
{ -cMqq$
try{ R@;kYS
Thread.sleep(nSecond); %/4ChKf!VR
} 0PZpE "$X
catch(Exception e) At"@`1n_u'
{ b8Y-!]F
e.printStackTrace (); }e1f kjWk
} h]I ^%7
} $~_TE\F1
X'O3)Yg
//日志 Wq]^1g_
public static void log(String sMsg) M4`qi3I
{ -_B*~M/vV`
System.err.println(sMsg); &kh-2#E
} 3~Ah8,
[V =O$X_
p?ICZg:
public static void log(int sMsg) xse8fGs
{ 8^kw
System.err.println(sMsg); dtJ?J<m}
} {"-uaH>,
} 3b~k)t4R
X"*pt5B6`
$)6y:t"
/* I_\j05
**TestMethod.java ih~ R?W
*/ !?,rcgi
package NetFox; 2Lm.;l4YO
ca5Ir<mL
NU O9,
public class TestMethod { /alJN`g
i,ga2{GnM
Ub3^Js!b%
public TestMethod() IvO#tI
{ ///xx/weblogic60b2_win.exe <8~bb-U$
try{ M/T ll]\|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )ui]vS:>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); eqV;4dhm
SiteFileFetch fileFetch = new SiteFileFetch(bean); Y$ZZ0m
fileFetch.start(); 4~4D1
} bs/Vn'CE
catch(Exception e){e.printStackTrace ();} (/JiOg^cw
uS;N&6;:
M$ CnaH
} F@UbUm2o
jhg0H2C8
wX[g\,?}'
public static void main(String[] args) IBZ_xU\2
{ ,:;ZzHzR0
new TestMethod(); ?`8jn$W^
} f<?v.5($
} E0G"B'x
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