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)); 538fK9[
} :*^:T_U
for(int i=0;i<nEndPos.length-1;i++) Vzpt(_><
{ 59.$ULQVMY
nEndPos = nStartPos[i+1]; X4a^mw\"
} }i(qt&U;
nEndPos[nEndPos.length-1] = nFileLength; !{;[xXK4M
} ! 0^;;'
} fV 3r|Bp
3filAGR?
z<hFK+j,'^
//启动子线程 Re>AsnA[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; l09Fn>wa
for(int i=0;i<nStartPos.length;i++) "u_i[[y
{ jAXR`D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), cv2]*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 2gt+l?O<PS
nStartPos,nEndPos,i); ^EF'TO$
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aR _NyA
fileSplitterFetch.start(); qP7G[%=v
} nTPB,QE<
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2UiR~P]%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GD!- qH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {;*}WPYb
nEndPos = " + nFileLength); ]bm=LA
// fileSplitterFetch[nPos.length-1].start(); </= CZy5w
5y]io Jc9-
>-M ]:=L
//等待子线程结束 #b'N}2'p#V
//int count = 0; %,/lqcFo
//是否结束while循环 $_sYfU9
boolean breakWhile = false; jo}1u_OJ
-ey)J +?t
TjxA#D)
while(!bStop) [& ^RP,N~
{ Ea-bC:>
write_nPos(); 4jQ'+ 2it
Utility.sleep(500); b^x07lO
breakWhile = true; Y&K <{\vE
@xS]!1-
[F+,YV%t
for(int i=0;i<nStartPos.length;i++) _-O cc=Z
{ &iqw! ud
if(!fileSplitterFetch.bDownOver) 3Hw[s0[$
{ ;FU|7L$H
breakWhile = false; }k7_'p&yk
break; YGp)Oy}:
} bHE7yv [
} nU2V]-qY
if(breakWhile) b0rX QMu
break; \:Za[6
=LI:S|[4
|f\D>Y%)
//count++; eZH~je{1
//if(count>4) x0A7O
// siteStop(); D^+?|Y@N
} <*<U!J-i
z}+i=cAN
]!Oue_-;
System.err.println("文件下载结束！"); )u*^@Wo
} GKZN}bOm\
catch(Exception e){e.printStackTrace ();} ?iv=53<c#
} :HRT 2I
y(5:}x&E
dY!u)M;~~
//获得文件长度 xr[Vp
public long getFileSize() s9O2k}]
{ CE ~@}`
int nFileLength = -1; Z(e^iH
try{ ?qmp_2:WU
URL url = new URL(siteInfoBean.getSSiteURL()); _'!kuE,*1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GS;%zdH~
httpConnection.setRequestProperty("User-Agent","NetFox"); e)@3m.
j+kC-U;
7C7>y/uS
int responseCode=httpConnection.getResponseCode(); 7O)" `
if(responseCode>=400) FOH@OY
{ \S ."?!U
processErrorCode(responseCode); booRrTS
return -2; //-2 represent access is error .TpsJXF
} Xgat-cy'DA
[&#/|zH'j:
I[d]!YI}F
String sHeader; <41ZZ0<EwY
NmpnJu|8
=lp1Z>
for(int i=1;;i++) eg<pa'Hw
{ )h_8vO2
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (dqCa[
//Utility.log(in.readLine()); =-#G8L%Q
sHeader=httpConnection.getHeaderFieldKey(i); QR0(,e$Dl
if(sHeader!=null) tU@zhGb
{ "35A/V
if(sHeader.equals("Content-Length")) o6a0'vU><
{ W\cjdd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }^%xvmQ\]
break; taWqSq!
} I:l01W;
} +v7) 1y
else [ MyE2^
break; UzG[:ic%
} Z7a945Jd
} ldqLM
catch(IOException e){e.printStackTrace ();} FwG!>
catch(Exception e){e.printStackTrace ();} <RXwM6G2
pQa:pX
' cIEc1y
Utility.log(nFileLength); /7"I#U^u/
[k<1`z3
{tiKH=&J
return nFileLength; [}z,J"Un
} ZZxk]D<
:"1|AJo)
]a'99^?\
//保存下载信息（文件指针位置） zjl!9M!
private void write_nPos() h6:#!Rg
{ wT,R0~V0
try{ cU.9}-)
output = new DataOutputStream(new FileOutputStream(tmpFile)); pUYM}&dX
output.writeInt(nStartPos.length); (?0`d
for(int i=0;i<nStartPos.length;i++) bHE2,;o
{ <vV_%uoM
// output.writeLong(nPos); aYn^)6^
output.writeLong(fileSplitterFetch.nStartPos); K> g[k_
output.writeLong(fileSplitterFetch.nEndPos); }G VX>p
} JRaq!/[(
output.close(); YHXLv#8
} g}LAks
catch(IOException e){e.printStackTrace ();} 0#_'o ,
catch(Exception e){e.printStackTrace ();} i3$$,W!
} fyknP)21I
Lgk
dT|vYK}\
//读取保存的下载信息（文件指针位置） XvTCK>1
private void read_nPos() hX:"QXx
{ \ 0W!4D
try{ zUJZ`seF
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); <y.]ImO
int nCount = input.readInt(); p>w]rE:}
nStartPos = new long[nCount]; b97w^ah4gJ
nEndPos = new long[nCount]; ULJmSe
for(int i=0;i<nStartPos.length;i++) o5U(i
{ AIYmS#V1W2
nStartPos = input.readLong(); $sHP\{
nEndPos = input.readLong(); !]yO^Ob.E
} KngTc(^_D
input.close(); 942lSyix
} =q7Z qP
catch(IOException e){e.printStackTrace ();} FS6`6M.K
catch(Exception e){e.printStackTrace ();} as yZe
} {i0SS
]:M0Kj&h
:rMM4
private void processErrorCode(int nErrorCode) I#F!N6;
{ w8S!%abl1
System.err.println("Error Code : " + nErrorCode); k <iTjI*N
} DyJ.BQdk)
EOj"V'!
<EO$]>;0
//停止文件下载 dO> VwP
public void siteStop() q[q?hQ/b
{ B%CTOi
bStop = true; }je,")#W
for(int i=0;i<nStartPos.length;i++) S-Y=-"
fileSplitterFetch.splitterStop(); f5AjJYq1
\wcam`f
{%lXYMyu
} 'rp }G&m
} bV+(b9
//负责部分文件的抓取 >@xrs
**FileSplitterFetch.java &Mq~T_S
*/ @hQlrq5c
package NetFox; Q/uwQo/
g- AHdYJ
[qUN4x5b
import java.io.*; c#-U%qZ
import java.net.*; M>9-=$7
fZ04!R
I-y#Ks1p+
public class FileSplitterFetch extends Thread { KqBk~-G
#} ~qqJ G2
-}O1dEn.
String sURL; //File URL vE@!{*
long nStartPos; //File Snippet Start Position ~(!XY/0e
long nEndPos; //File Snippet End Position f`9 b*wV
int nThreadID; //Thread's ID 0sN.H=
boolean bDownOver = false; //Downing is over N{ Z H
boolean bStop = false; //Stop identical An;MVA
FileAccessI fileAccessI = null; //File Access interface 5pr"d@.
+/,icA}PI
@SZM82qU2z
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException {^(ACS9mL
{ ?0? R
this.sURL = sURL; Q_* "SRz
this.nStartPos = nStart; S5~VD?O,
this.nEndPos = nEnd; -p3Re9
nThreadID = id; Bjk]ZU0T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 A+6 n#
} \drqG&wl
(py]LBZ
w0w G-R ?
public void run() G'3qzBJ#
{ G9g1hie@%
while(nStartPos < nEndPos && !bStop) O"Ku1t!
{ il|1a8M2~
* #jsgj[
| N0Z-|
try{ q0f3="
URL url = new URL(sURL); ^O^l(e!3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lY|Jr{+Ln
httpConnection.setRequestProperty("User-Agent","NetFox"); dJT]/g
String sProperty = "bytes="+nStartPos+"-"; %K(<$!
httpConnection.setRequestProperty("RANGE",sProperty); pw7[y^[Qg
Utility.log(sProperty); @u==x*{|
fP.F`V_Y
WVVJ
InputStream input = httpConnection.getInputStream(); f|O{#AC
//logResponseHead(httpConnection); o-}R?>
:ba5iMa
O@p]KSfk
byte[] b = new byte[1024]; 311LC cRp
int nRead; :Ad&$eg+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t#q<n:WeYU
{ pZ/>[TP(%F
nStartPos += fileAccessI.write(b,0,nRead); ': N51kC
//if(nThreadID == 1) /~x"wo
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); EEGy!bff
} ZPbpp@,
nstUMr6
yAoe51h?
Utility.log("Thread " + nThreadID + " is over!"); B6wRg8
bDownOver = true; | WvUq
//nPos = fileAccessI.write (b,0,nRead); w)Covz'uf
} @V03a )6,h
catch(Exception e){e.printStackTrace ();} dtpoU&?6s
} XC.%za8
} @|Rrf*J?%
^f# FI&
os/vtyP:a
//打印回应的头信息 [IK )
public void logResponseHead(HttpURLConnection con) R: l&2k@
{ V}\~ugN)y
for(int i=1;;i++) bV ZMW/w
{ zN [2YJ$
String header=con.getHeaderFieldKey(i); eImn+_ N3
if(header!=null) X7s `U5'l
//responseHeaders.put(header,httpConnection.getHeaderField(header)); (V4 ~`i4V
Utility.log(header+" : "+con.getHeaderField(header)); 6R=W}q4
else Q+YRf3$
break; OE}*2P/M>
} dd]/.Z
} lsJnI|
!?|Th5e
ANgw"&&>(
public void splitterStop() 9<KAXr#
{ 1Tu *79A
bStop = true; O%FPS=
} S#+h$UVh
Th=eNL]
lV%N
} L'u\w
@|\}.M<e*)
=jN*P?
/* }Hn/I,/
**FileAccess.java O} f80K
*//文件访问(定位，写) ?Wz8[u
package NetFox; eopD5
import java.io.*; TYy.jFT-
V{JAB]?^
j$+nKc$
public class FileAccessI implements Serializable{ TA{\PKA)
]Ux<aiY]a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5H ue7'LS
RandomAccessFile oSavedFile; 8 XU1/i7N
long nPos; 1Z9qjV%^
3+XOZh8
3`k;a1Z#O'
public FileAccessI() throws IOException Zl*X?5u
{ KQ~i<1&j
this("",0); rb|U;)C
} [i]Ub0Dh7
%"P,1&\^
Dc_yM
public FileAccessI(String sName,long nPos) throws IOException kXf'5p1
{ 1PpyVf
oSavedFile = new RandomAccessFile(sName,"rw"); qzTuxo0B
this.nPos = nPos; 9]@A]p!
oSavedFile.seek(nPos); d+'p@!W_
} bFW=ylF9
@7B$Yy#
DCZ\6WY1G)
public synchronized int write(byte[] b,int nStart,int nLen) +(h\fm7*-
{ ?Orxmxc 2
int n = -1; t2lS ~l)
try{ QDu2?EYZq
oSavedFile.write(b,nStart,nLen); o#skR4lwe
n = nLen; U-|NY
} uXKERzg
catch(IOException e) Ry'= ke
{ jrS[f
e.printStackTrace (); 1&- </G#
} {DR`;ea])1
[<6S%s
$g sxO!G
return n; B#M5}QT|2
} Rp5#clsy
|]c8jG\h
DK$s&zf
} Qc pm!
R;j!}D!4
:AE&Ny4
/* <>8WQn,K
**SiteInfoBean.java ` eXaT8
*/ 'nwx9]q
package NetFox; & 9<+;*/
w'm;82V:P-
&sU?Ok6
public class SiteInfoBean { w'UVKpG+
TTKs3iTXz
PF53mUs4
private String sSiteURL; //Site's URL FAj)OTI2S
private String sFilePath; //Saved File's Path +1D+]*t_?[
private String sFileName; //Saved File's Name 'L8' '(eZ^
private int nSplitter; //Count of Splited Downloading File R.yC(r
i(NdGL#P
fP. 6HF_p_
public SiteInfoBean() sNLs\4v
{//nSplitter的缺省值为5 aXoVy&x=
//default value of nSplitter is 5 (,8$V\
this("","","",5); H(Z88.OM
} MerFZd 1
@WVcY:1t#
/@,j232
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 6=fSE=]DY
{ 0`[wpZ
sSiteURL= sURL; P9vA7[
sFilePath = sPath; {62n7'U{
sFileName = sName; d&+h}O
this.nSplitter = nSpiltter; cj1cZ-
ekWePL;rR2
FN8NTBk
} CL+}|7O(
#N`~xZ|$
<kx&w(=
public String getSSiteURL() L{8xlx`
{ !y@6Mm
return sSiteURL; CW,Wx:Y
} DKBSFm{~Q
%y@Hh=
p{j.KI s7
public void setSSiteURL(String value) <psZQdH
{ .n~M(59
sSiteURL = value; AD|2qM))
} ~x]jB
Yo|,]X>/
<c2'0I >
public String getSFilePath() ~,i-8jl,
{ `pGa~!vl
return sFilePath; lx[oaCr
} OUhqMVX9C
Kq;8=xP[
z}MP)|aH:
public void setSFilePath(String value) /,g,Ch<d
{ 'coV^~qy
sFilePath = value; pLLGus+W
} t},/}b
%>g3~yl
j4cwI90=
public String getSFileName() 2(#7[mgPI
{ 0sfr d
return sFileName; Yi$vg
} 61)-cVC
*q-['"f
U G~ba
public void setSFileName(String value) +,#$:fs u
{ TzNn^ir=HX
sFileName = value; /assq+H
} {/ BT9|LI
qLB)XnQ
Ht&:-F+dm
public int getNSplitter() AMyIAZnYq)
{ B>0].CK`
return nSplitter; V{:A3C41
} USM4r!x
xUa{1!Y8
YLiSbLz1
public void setNSplitter(int nCount) M!REygyx
{ IVAmV!.z
nSplitter = nCount; =AEBeiz
} pQtJc*[!
} 'a\%L:`
G}ob<`o|"
>8qQK r\"
/* paD!Z0v&
**Utility.java 7r~~Y%=C|
*/ B4i!/@0s
package NetFox; g.zEn/SM
3%%o?8ES
fR*q?,
public class Utility { f (F)1
U qFv}VsnF
"saUai4z
public Utility() 6{^E{go
{ Is{KN!Hw
,Q HU_jt
u (em&M
} 9mmCp&~Z
ucG@?@JENm
//线程睡眠 b"#WxgaF
public static void sleep(int nSecond) Y}#J4i0b*
{ QT>`^/]d
try{ U8LtG/
Thread.sleep(nSecond); 2gCX}4^3b
} er!DYv
catch(Exception e) -\ EP.Vtz
{ DUC#NZgw
e.printStackTrace (); !>zo_fP
} o1h={ao
} .U?'i<
L>SjllY
//日志 +ayos[<0#
public static void log(String sMsg) j]aoR
{ :uK?4
System.err.println(sMsg); /Q2mMSK1h
} 4:dH]
+gJ8{u!=k
o!{w"K
public static void log(int sMsg) Q2F+?w;,
{ o'f?YZ$.
System.err.println(sMsg); t ]_VG
} Pyb Z)5u
} LRb{hUt=
A<qTg`gA
xK6n0] A
/* I~Zh@d%
**TestMethod.java n=c 2Kc
*/ &' Ne!o8
package NetFox; 9&_<f}ou
(<}&DE
bdF.qO9
public class TestMethod { t 0|!(3
)`A3M)
Vc2A
public TestMethod() [ji#U s:h
{ ///xx/weblogic60b2_win.exe o8-^cP1
try{ sU@nc!&Y@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .QN>z-YA6:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \0vr>C
SiteFileFetch fileFetch = new SiteFileFetch(bean); ] 0B2# d
fileFetch.start(); jkt_5+S
} 2L} SJUk*
catch(Exception e){e.printStackTrace ();} g#t[LI9(F[
!VI]oRgP
DIzH`|Y
} b+&%1C
|qmu_x\
gm[z[~X@
public static void main(String[] args) {yB&xj[z
{ Y[K*57fs
new TestMethod(); 8=Z9T<K
} "vyNxZE
} 3T!lA
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