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)); \r IOnZ.WK
} Hpix:To
for(int i=0;i<nEndPos.length-1;i++) +1wEoU.l2
{ 1R}9k)JQ
nEndPos = nStartPos[i+1]; n=-vOa%
} 1<vJuF^
nEndPos[nEndPos.length-1] = nFileLength; wxHd^b
} X.#*+k3s0
} y7pBcyWTE=
OFr"RGW"
gqv+|:#
//启动子线程 IER;d\_V<
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;cVK2'
for(int i=0;i<nStartPos.length;i++) }`L;.9
{ =-oP,$k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), yr},pB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), n*9QSyJN]
nStartPos,nEndPos,i); S!A:/(^WB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @2"uJ6o
fileSplitterFetch.start(); Ct `)R
} #v(As)4^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), DTC IVLV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); FZgf"XM>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Zw)=Y.y!
nEndPos = " + nFileLength); )vq}$W!:9
// fileSplitterFetch[nPos.length-1].start(); $@6q5Iz!&
(72%au
Dl.<(/
//等待子线程结束 (^~a1@f,J
//int count = 0; K_+M?ap_
//是否结束while循环 ED8{
boolean breakWhile = false; (tA[]ne2
jkl dr@t
U>kaQ54/
while(!bStop) (A2ga):Pk
{ 06HU6d,
write_nPos(); ?MywA'N@x
Utility.sleep(500); 7J3A]>qU
breakWhile = true; +ase>'<N#
"zw{m+7f,
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for(int i=0;i<nStartPos.length;i++) JVg}XwR
{ ~<u\YIJ
if(!fileSplitterFetch.bDownOver) c@,1?q1bv
{ Fdl0V:<
breakWhile = false; f]10^y5&
break; yx#!2Z0hw
} }{:Jj/d p
} .Od@i$E>&
if(breakWhile) E<LH-_$
break; V?t*c [
X7*ossv
R[j'<gd.
//count++; YP!}Bf
//if(count>4) F+G+XtOS
// siteStop(); 9/8+R%
} V9ZM4.,OCN
6 [bQ'Ir^8
N\ <riS9
System.err.println("文件下载结束！"); }qGd*k0F0
} wy|b Hkr_
catch(Exception e){e.printStackTrace ();} i*l=xW;bM
} xX%{i0E
IRLAsb3
"$5cKbJ
//获得文件长度 TyO]|Q5
public long getFileSize() S9*68l
{ KD\%B5Jy
int nFileLength = -1; D|Tz{DRG
try{ Bs3&yEq(
URL url = new URL(siteInfoBean.getSSiteURL()); on hLhrZ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); mb_6f:Qh3
httpConnection.setRequestProperty("User-Agent","NetFox"); DIYR8l}x
"&qAV'U
w[vccARQ
int responseCode=httpConnection.getResponseCode(); k0FAI0~(
if(responseCode>=400) a"}ndrc*
{ ]/p>p3@1C
processErrorCode(responseCode); EFU)0IAL[
return -2; //-2 represent access is error ENA"T-p
} $2]>{g
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>t9DI
String sHeader; 2ETv H~23
MYJMZ3qBi
1e9~):C~W
for(int i=1;;i++) KWYjN h#*
{ 3it*l-i\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,y0 &E8Z
//Utility.log(in.readLine()); kxrYA|x
sHeader=httpConnection.getHeaderFieldKey(i); SPe%9J+
if(sHeader!=null) cAx$W6S
{ ,ZYPffu<*
if(sHeader.equals("Content-Length")) }]1C=~lC
{ `)8SIx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3 %BI+1&T_
break; F1}d@^K 7d
} o]]tH
} m+dQBsz\
else g^:`h VV
break; RHd no C
} s,mt%^x[
} /ZL6gRRA|
catch(IOException e){e.printStackTrace ();} non5e)w3@
catch(Exception e){e.printStackTrace ();} !mVq+_7]
r^E(GmW
_iA oNT!
Utility.log(nFileLength); Bs '=YK$
kTzO4s?
[@pumH>
return nFileLength; `S3)uV]I
} :v45Ls4J
vEE\{1
Vv`94aQTD
//保存下载信息（文件指针位置） av'[k<
private void write_nPos() ^VnnYtCRz
{ 71IM`eL=ED
try{ S%?%06$
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?hrz@k|
output.writeInt(nStartPos.length); }YiFiGf,
for(int i=0;i<nStartPos.length;i++) _9=cxwi<w
{ !u:;Ew
// output.writeLong(nPos); '19?
output.writeLong(fileSplitterFetch.nStartPos); Tqs|2at<t
output.writeLong(fileSplitterFetch.nEndPos); J}bLp Z
} i}f"'KW
output.close(); (B*,|D[J@i
} l"h6e$dP
catch(IOException e){e.printStackTrace ();} 9[&q C
catch(Exception e){e.printStackTrace ();} 6\UIp#X
} t8lGC R
,l,q;]C%
"fN 6_*
//读取保存的下载信息（文件指针位置） oBnes*
private void read_nPos() YJDJj x
{ AnE] kq u
try{ @d0~'_vtB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); oOLj? 0t
int nCount = input.readInt(); W8-vF++R
nStartPos = new long[nCount]; dtG>iJ
nEndPos = new long[nCount]; gL@]p
for(int i=0;i<nStartPos.length;i++) O"X7 DgbC
{ GUJ?6;
nStartPos = input.readLong(); WFmW[< g
nEndPos = input.readLong(); [_KOU2
} zTq"kxn'
input.close(); %5n'+-XVj
} e?o/H
catch(IOException e){e.printStackTrace ();} p&2d&;Qo0
catch(Exception e){e.printStackTrace ();} (_N(K`4#W
} U9\w)D|+eE
s|[qq7
<&((vrfa
private void processErrorCode(int nErrorCode) 3/c%4b.Z
{ ts,V+cEA
System.err.println("Error Code : " + nErrorCode); *k?y+}E_f
} Hh&qjf
Osy_C<O
JPZH%#E(
//停止文件下载 # xX
public void siteStop() @'Pay)P
{ CLuQ=-[|
bStop = true; :S-{a
for(int i=0;i<nStartPos.length;i++) #B!M,TWf9s
fileSplitterFetch.splitterStop(); k2#|^N
wT,=C'
(*T$:/zIS
} 2P=~6(
} fL-$wK<p<
//负责部分文件的抓取 Vhe$vH
**FileSplitterFetch.java u3Zu ~C
*/ [4yw? U
package NetFox; P*ZMbAf.
:+?rnb)N
93,7yZ5#
import java.io.*; Le/}xST@
import java.net.*; %z~kHL
fMM%,/b{
hdmKD0
public class FileSplitterFetch extends Thread { 00r7trZW^
=<K6gC27
Bf[`o<c
String sURL; //File URL i{Du6j^j
long nStartPos; //File Snippet Start Position gC_KT,=H;
long nEndPos; //File Snippet End Position N&$ ,uhmO
int nThreadID; //Thread's ID U?5G%o(q
boolean bDownOver = false; //Downing is over :FmH=pI!=
boolean bStop = false; //Stop identical Wn?),=WQ{
FileAccessI fileAccessI = null; //File Access interface bFH`wLW
(Y^tky$9
r'o378]=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i If?K%M7
{ 50T^V`6
this.sURL = sURL; _S-@|9\&#
this.nStartPos = nStart; v}IhO~`uEq
this.nEndPos = nEnd; Otf{)f
nThreadID = id; & Yx12B\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 }iUpBn
} _lm^v%J$
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wAL}c(EHO
public void run() #veV {,g
{ p|BoEITL
while(nStartPos < nEndPos && !bStop) %E [HMq<H
{ U: )Gc
q_9 tbZ;
Wu$yB!
try{ DhsvN&yNM
URL url = new URL(sURL); )ac!@slb^7
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LPca+o|f
httpConnection.setRequestProperty("User-Agent","NetFox"); |TR +Wn
String sProperty = "bytes="+nStartPos+"-"; _]eyt_
httpConnection.setRequestProperty("RANGE",sProperty); qmvQd8|XR
Utility.log(sProperty); ',rK\&lL6
(I35i!F+tY
47f\
InputStream input = httpConnection.getInputStream(); @*|T(068&
//logResponseHead(httpConnection); uotW[L9
~sq@^<M)s
GY^;$?
byte[] b = new byte[1024]; <num!@2D
int nRead; H(y Gh
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Bx5kqHp^1
{ 64>CfU(
nStartPos += fileAccessI.write(b,0,nRead); ,g,Hb\_R)
//if(nThreadID == 1) K{B|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ovDPnf(
} Y4_xV&
|f.,fVVV;
( 5uSqw&U
Utility.log("Thread " + nThreadID + " is over!"); v53|)]V
bDownOver = true; %}XyzGq{
//nPos = fileAccessI.write (b,0,nRead); w8 `1'*HG
} k_Y7<z0G
catch(Exception e){e.printStackTrace ();} es=OWJt^
} Ki&a"Fu3
} YBF$/W+=9|
<$otBC/%
Htln <N
//打印回应的头信息 WJ[>p ELT,
public void logResponseHead(HttpURLConnection con) 4%I[.dBnM
{ SQ/HZ
for(int i=1;;i++) ,xAF=t
{ A5%$<
String header=con.getHeaderFieldKey(i); ,H^!G\
if(header!=null) brlbJFZ19
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ED>a'y$f
Utility.log(header+" : "+con.getHeaderField(header)); y*v|q=
else >7S@3,C3ke
break; ]0j_yX
} /H3w7QU
} mZjpPlJ
xtLP4VL
x;Slv(|M
public void splitterStop() _+(@?
{ ,|.}6\zl*{
bStop = true; ik;F@kdm`
} Chx+p&!
;oDr8a<A
-|>T? t'K
} EbVva{;#$;
i" )_Xb_1
nj0]c`6rN@
/* l=((>^i
**FileAccess.java ek0!~v<I
*//文件访问(定位，写) X8N9*vy
package NetFox; 3wcFR0f
import java.io.*; JY^i
&g1\0t
a60rJ#GD
public class FileAccessI implements Serializable{ Mw)6,O`
cUdS{K&K
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 J_m@YkK
RandomAccessFile oSavedFile; $ ]#WC\Hv
long nPos; As`=K$^Il.
n${k^e-=
r\Yh'cRW{
public FileAccessI() throws IOException KLE)+|
{ \iP@|ay9
this("",0); c %Cbq0+2
} HEIg_6sb
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(Cfb8\~
public FileAccessI(String sName,long nPos) throws IOException 2CneRKQy
{ i. (Af$
oSavedFile = new RandomAccessFile(sName,"rw"); 5b*knN>
this.nPos = nPos; Zj'%c2U_
oSavedFile.seek(nPos); 0\X<vrW
} i1-%#YYF(
/]MelW
%Ta"H3ZW
public synchronized int write(byte[] b,int nStart,int nLen) x\f~Gtt7Y
{ Gn_DIFa
int n = -1; (V]3w
try{ P)J-'2{
oSavedFile.write(b,nStart,nLen); 't0M+_J
n = nLen; j%^4 1y
} Y?3tf0t/
catch(IOException e) hpPacN
{ y$SUYG'v
e.printStackTrace (); |5O>7~Tp
} ^\?Rh(pu
nPqpat`E
.9PT)^2
return n; ) ba~7A
} lv'WRS'}
'?L^Fa_H
kLZVTVSJt
} ' BS.:^
(;%T]?<9#
&ah%^Z4um
/* oW6Hufu+o
**SiteInfoBean.java t"q'"FX
*/ vc&+qI+I3
package NetFox; ?_Z-}f
RLB"}&SF]
dIlpo0; F
public class SiteInfoBean { ||awNSt
bvB',yBZ
dnU-v7k,{
private String sSiteURL; //Site's URL J:Qx5;b;
private String sFilePath; //Saved File's Path /Xb4'Qj
private String sFileName; //Saved File's Name Y%;X7VxU*
private int nSplitter; //Count of Splited Downloading File NR1M W^R
k4{|Xn
s(3HZ>qx;
public SiteInfoBean() H@?} !@
{//nSplitter的缺省值为5 'ET];iZ2
//default value of nSplitter is 5 o,dp{+({
this("","","",5); 9&AO
} Ohp@ZJ!a?
,}gJY^X+
6&ut r!\7
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e'G=.:
{ Y$A2{RjRq
sSiteURL= sURL; ng!cK<p
sFilePath = sPath; i\ X3t5
sFileName = sName; +KIz#uqF8Z
this.nSplitter = nSpiltter; X~0-WBz
_#:7S sJ
OB$Jv<C@
} pTwzVz~
Pd"c*n&9
a'?;;ZC-
public String getSSiteURL() a(]&H "
{ pka^7OWyN
return sSiteURL; ~1wt=Ln>
} tjb$MW$('
TZt;-t`
A%Ka)UU+n
public void setSSiteURL(String value) Pg(Y}Tu
{ oMj"l#a*
sSiteURL = value; $) "\N
} RBn/7
h]ae^M
L,y q=%h|
public String getSFilePath() 8xgBNQdPT
{ jc Mn
return sFilePath; o?>0WSLlm
} ]$r]GVeN}H
yVmp,""a
aO&{.DO2
public void setSFilePath(String value) A_wf_.l4h
{ Yz_}*
sFilePath = value; x-CjxU3
} B#%QY\<X
iIX%%r+
A'z]?xQR
public String getSFileName() Ia}qDGqPp!
{ h$!YKfhq}
return sFileName; @i>)x*I#AI
} BNCM{}e
'`k7l7I[@
|ffHOef
public void setSFileName(String value) K?'m#}]
{ )2?]c
sFileName = value; zMbFh_dcq
} 18rV Acj
Y:TfD{Xgc
QjY}$
public int getNSplitter() ~ O#\$u
{ SQ4^sk_!
return nSplitter; z:f&k}(
} g]?pY
zl:by?
6LCtWX
public void setNSplitter(int nCount) p7Wt(A
{ }vZf&ib-
nSplitter = nCount; -^m?%_<50l
} xn2nh@;
} 0q"4\#4l
2{b/*w
$5 mGYF]
/* 3Jizv,?
**Utility.java SqPqL<,e
*/ ?g+3 URpK
package NetFox; lOVcXAe}
7gf(5p5ZV
q=88*Y
public class Utility { (x2?{\?
q x)\{By
erEB4q+ #O
public Utility() #U`AK9rP_g
{ 1*hEbO
_dd! nU\A|
kiM:(=5
} -z`FKej
O00;0wu
//线程睡眠 tJ;qZyy(
public static void sleep(int nSecond) MQwxQ{
{ ]Wkgpfd56
try{ M@{?#MkS%
Thread.sleep(nSecond); qG;tD>jy
} 1}wDc$O
catch(Exception e) ;99oJD,
{ d9S/_iCI
e.printStackTrace (); 68u?}8}
} m*_X PY
} BN79\rt
xS1n,gTA
//日志 3Y38lP:>h
public static void log(String sMsg) p\=T#lb
{ S~aWun
System.err.println(sMsg); 3XQa%|N(
} >(a35 b$
#8et91qw
]`$yY5&W0
public static void log(int sMsg) r!Dk_|Cd
{ pL{oVk#,
System.err.println(sMsg); ;"Gy5
} \"ahs7ABT
} Bz }nP9
FM6{%}4
EF :g0$
/* mh}D[K=~%
**TestMethod.java Jd7chIK
*/ _:9}RT?
package NetFox; ~4~r
*?t$Q|2Xr
c0Ih$z
public class TestMethod { UnK7&Uo
KuJ9bn{u!C
?P+Uv
public TestMethod() eX#.Zt]
{ ///xx/weblogic60b2_win.exe ;B 8Q,.t>x
try{ .hx(9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &YY`XEG59O
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o~XK*f=(
SiteFileFetch fileFetch = new SiteFileFetch(bean); *S*49Hq7c
fileFetch.start(); 4E.9CjN1>
} <?B3^z$
catch(Exception e){e.printStackTrace ();} '/xynk%)xw
=?C <@
} TUr96
} &7\}Sqp
y]yl7g =~
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public static void main(String[] args) eXKEx4rU
{ A4f"v)vM
new TestMethod(); 2*75*EQCH
} U3&GRY|##
} TXi|
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