http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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<,/gj
} X\Y}oa."A
for(int i=0;i<nEndPos.length-1;i++) F8<"AI
{ G2`${aMS
nEndPos = nStartPos[i+1]; hQRL,?
} vE%s,E,
nEndPos[nEndPos.length-1] = nFileLength; ~6`iY@)
} *5k+t
} FJeiY#us
gAt~?HvW6
h}Rx_d
//启动子线程 i?>tgmu.
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0:"2MSf>
for(int i=0;i<nStartPos.length;i++) mdW~~-@H
{ VWx]1\
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %MZP)k,&U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ` #OSl
nStartPos,nEndPos,i); Xc*U+M>U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %'bJ:
fileSplitterFetch.start(); VfSj E.|
} e_.Gw"/Yl
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6)qp*P$L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rh!;|xB|+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", |mhKIis U
nEndPos = " + nFileLength); eQUe >*
// fileSplitterFetch[nPos.length-1].start(); +5!&E7bcd
{u"8[@@./
Apj;
//等待子线程结束 H4:&%"j7
//int count = 0; s$w;q\1z
//是否结束while循环 LlHa5]E@6
boolean breakWhile = false; edipA P~!
kJ{+M]pW
%Jp|z? [/
while(!bStop) aI3CNeav
{ _{4^|{>Pv
write_nPos(); fBhoGA{=g
Utility.sleep(500); !m;H@KR{
breakWhile = true; ml6u1+v5
Ag9?C*
iafE5b)
for(int i=0;i<nStartPos.length;i++) ]y#3@
{ _,haD)1g~
if(!fileSplitterFetch.bDownOver) }!p`1]gem
{ NI aFI(
breakWhile = false; u0QzLi,
break; :nA.j"@
} 6*45Vf
} =-"c*^$]
if(breakWhile) NX[4PKJ0C
break; /Fgw$ ^H
dOFD5}_
aC%&U4OS
//count++; @n-r-Q
//if(count>4) )5_jmW`n
// siteStop(); ^7^N}x@
} e}hmS1>H
'n;OB4
)G~w[~
System.err.println("文件下载结束！"); Ts.wh>`
} 8|6 4R:
catch(Exception e){e.printStackTrace ();} $q$7^r@
} i/H+xrCK
CyDV r
<\ `$Jx#
//获得文件长度 GZip\S4Y
public long getFileSize() A\fb<
{ l12{fpm
int nFileLength = -1; g[H',)A)
try{ asHxL!
URL url = new URL(siteInfoBean.getSSiteURL()); as*4UT3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TX=yPq
httpConnection.setRequestProperty("User-Agent","NetFox"); IQZ#-)[T"
83%)/_&
lf(`SYQnOY
int responseCode=httpConnection.getResponseCode(); !-<p,z
if(responseCode>=400) MUnEuhXTr
{ [F!Y%Zp
processErrorCode(responseCode); A@hppaP!
return -2; //-2 represent access is error U8.7>ENnP&
} _>+8og/%@
]hos+;4p
+{<#(}
String sHeader; ":a\z(*t
U*3J+Y
YNwp/Y
for(int i=1;;i++) km~Ll
{ bKg8rK u
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2i;7{7
//Utility.log(in.readLine()); :cB=SYcC%
sHeader=httpConnection.getHeaderFieldKey(i); oVFnlA
if(sHeader!=null) ;oZ)Wt
{ R;,g1m|]
if(sHeader.equals("Content-Length")) >/[GTqi
{ >NYW{(j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wX >*H
break; #$1Z
} k:jSbbQ
} I[)%,jd
else mKrh[nA
break; 7xRl9
} &xRo^iV?
} wE+${B03
catch(IOException e){e.printStackTrace ();} n3AaZp[
catch(Exception e){e.printStackTrace ();} (aOv#Vor]%
{9UEq0
ry9T U
Utility.log(nFileLength); >B]'fUt5a
x }Ad_#q
'AN>`\mR$
return nFileLength; hn#1%p6t
} q`-;AG|xF
(x/k.&
X 1 57$
//保存下载信息（文件指针位置） okbQ<{9
private void write_nPos() DC{>TC[p1k
{ rj(T~d4
try{ }gJ(DbnV
output = new DataOutputStream(new FileOutputStream(tmpFile)); 93Co}@Y;Y+
output.writeInt(nStartPos.length); 3EJt%}V$k
for(int i=0;i<nStartPos.length;i++) :VTTh |E%#
{ ULMu19>
// output.writeLong(nPos); xJ#d1[kzo
output.writeLong(fileSplitterFetch.nStartPos); ;4Y%PVz~D
output.writeLong(fileSplitterFetch.nEndPos); D$t k<{)oB
} ^#-nE7
output.close(); DI+fwXeg
} qkiI/nH3
catch(IOException e){e.printStackTrace ();} u\C lP#
catch(Exception e){e.printStackTrace ();} ` ,SiA-3*
} t+9][Adf
v`M3eh@$A
dKdj`wB
//读取保存的下载信息（文件指针位置） d_IAs
private void read_nPos() &mb{.=
{ hCC<?5q
try{ On?p 9^9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 8-2cRs
int nCount = input.readInt(); =Xo =Qcr
nStartPos = new long[nCount]; :Nz9xD$S5
nEndPos = new long[nCount]; J+`VujWT
for(int i=0;i<nStartPos.length;i++) ."9];)2rx
{ B)0i:"q
nStartPos = input.readLong(); AvfNwE
nEndPos = input.readLong(); y&V@^"`
} 9I4K}R
input.close(); rx] @A
} ax(c#
catch(IOException e){e.printStackTrace ();} V#iPj'*
catch(Exception e){e.printStackTrace ();} V,%=AR5
} S:OO0<W
xL\0B,]
thI F&
private void processErrorCode(int nErrorCode) >r!|sC
{ $m/)FnU/
System.err.println("Error Code : " + nErrorCode); ZjF 4v
} oz,e/v8~
s,]z[qB#$
zx)z/1
//停止文件下载 +mn,F};
public void siteStop() , GP?amh
{ HhvdqvIEG
bStop = true; x^y'P<ypw
for(int i=0;i<nStartPos.length;i++) y!_C/!d
fileSplitterFetch.splitterStop(); %^ !,t:d
JU)dr4S?
v_DedVhe
} 5yP\I+Fm
} )v.=jup[
//负责部分文件的抓取 MB]<Dyj,
**FileSplitterFetch.java 8|\8O@
*/ a6uJYhS~
package NetFox; |>dI/_'
fTK3,s1=
?`PvL!'
import java.io.*; lE4HM$p
import java.net.*; _sTROd)Vh
)8$=C#qC[
^G}47(
public class FileSplitterFetch extends Thread { tM'P m
=Jyu4j *}
iMDM1}b
String sURL; //File URL Xg;}R:g '
long nStartPos; //File Snippet Start Position }khV'6"'|
long nEndPos; //File Snippet End Position ~v|>xqWV
int nThreadID; //Thread's ID `u&Rsz&^
boolean bDownOver = false; //Downing is over xD~5UER
boolean bStop = false; //Stop identical DK:o]~n
FileAccessI fileAccessI = null; //File Access interface q1d}{DU
Yp^rR }N
+[\FD; >
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `T5W}p[6
{ ]1#e#M]#
this.sURL = sURL; Yfzl%wc
this.nStartPos = nStart; Ju1D =b
this.nEndPos = nEnd; @~"h62=] -
nThreadID = id; Ng~FEl
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H[U!%Z
} 3cK I
0tT(W^ho g
1SCR.@k<
public void run() {tYZt4!{^
{ %N>%!m
while(nStartPos < nEndPos && !bStop) V{/?FO?E
{ @1o/0y"
q_MG?re
__G?0*3G
try{ \o*5
URL url = new URL(sURL); )<h*eS{
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KY$)#i
httpConnection.setRequestProperty("User-Agent","NetFox"); >4TaP*_
String sProperty = "bytes="+nStartPos+"-"; r\'A i6
httpConnection.setRequestProperty("RANGE",sProperty); o$jLzE"
Utility.log(sProperty); uKUiV%p!
g| I6'K!<
O;:mCt _H
InputStream input = httpConnection.getInputStream(); (MxQ+D\
//logResponseHead(httpConnection); MOQ*]fV:
v$?+MNks
| *2w5iR
byte[] b = new byte[1024]; "n(hfz0y%
int nRead; >UiYL}'br6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ^ *k?pJ5
{ W$hx,VEy`
nStartPos += fileAccessI.write(b,0,nRead); &=] ~0$
//if(nThreadID == 1) N8F~8lTi
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); IP xiV]c
} r*2+xDoEi
Ug>~Rq]
`ZYoA t]C~
Utility.log("Thread " + nThreadID + " is over!"); V5V bJBpf
bDownOver = true; /Kql>$I
//nPos = fileAccessI.write (b,0,nRead); gY/"cq
} {Aw#?#GPW
catch(Exception e){e.printStackTrace ();} iT3BF"ZqBO
} /R]U}o^/(%
} tdBm (CsN
N +Yxz;Mg
GfoLae
//打印回应的头信息 [8 ]z|bM
public void logResponseHead(HttpURLConnection con) AG`L64B
{ A5c%SCq;
for(int i=1;;i++) KX,S
{ ;=)k<6
String header=con.getHeaderFieldKey(i); wh$sn:J
if(header!=null) <\rT%f}3^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UZ\u;/}
Utility.log(header+" : "+con.getHeaderField(header)); 4":KoS`,j
else V_:1EBzz
break; 4;e5H_}Oo
} p& y<I6a,
} AYqX|
81? hY4
nLbFg0?+t
public void splitterStop() h\fjBDU^
{ ^ Edfv5
bStop = true; X5zDpi|Dq
} +rd|A|hRq
vyNxT*,[K
kbX8$xTM
} _hAcJ{Y
8]M;T>n[
'f!8DGix
/* V,lOt4b
**FileAccess.java eenH0Ovv
*//文件访问(定位，写) W <9T0sZ
package NetFox; ,1~"eGl!
import java.io.*; (y=C_wvqZ
Uf1!qP/H?
DEBB()6,
public class FileAccessI implements Serializable{ x!?u^
Fe# 1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4n#M
RandomAccessFile oSavedFile; HCIU!4rH
long nPos; =Z{O<xw'
y8d]9sX{
8Q.T g.
public FileAccessI() throws IOException ])[[ V!1
{ OyStqi
this("",0); )\1QJ$-M&
} KKb,d0T[
u0}vWkn\4
sv2A-Dld
public FileAccessI(String sName,long nPos) throws IOException AgWa{.`f:
{ &9.Cl;I
oSavedFile = new RandomAccessFile(sName,"rw"); WEw6He;
this.nPos = nPos; ,cXD.y
oSavedFile.seek(nPos); )1Y{Q Y}l
} |5X^u+_
pf]xqhL
Rm2yPuOU}A
public synchronized int write(byte[] b,int nStart,int nLen) zKyyU}LHH
{ b10cuy|a/X
int n = -1; tl[Uw[
try{ N,<uf@LQ
oSavedFile.write(b,nStart,nLen); B*eC3ok3z
n = nLen; X1:V<,}"
} 5u,{6
catch(IOException e) C>]0YO k2
{ oro$wFxJO
e.printStackTrace (); 0B[="rTS7#
} aacpM[{f
\J4L:.`qS
rbul8(1h
return n; &r[`>B{tP
} DKH-Q(M56
):P?
AKY1o.>z
} _1!7V3|^
m1j*mtu
EHSlK5bD,
/* mJ<=n?{Z
**SiteInfoBean.java k}S :RK
*/ {k(g]#pP
package NetFox; W4t;{b
{Je[ZQ$
gBd]B03
public class SiteInfoBean { Z3%}ajPu[
CVDV)#JA
oxr#7Ei0d
private String sSiteURL; //Site's URL @MoKWfc
private String sFilePath; //Saved File's Path ,1hxw<sNR
private String sFileName; //Saved File's Name .4S.>~^7
private int nSplitter; //Count of Splited Downloading File )tG\vk=@
}?lrU.@zg
cv8L-Z>x.=
public SiteInfoBean() Pi=+/}
{//nSplitter的缺省值为5 V#v`(j%
//default value of nSplitter is 5 QZ!Y2Bz(4
this("","","",5); -Mip,EO
} 9q)Kfz
AWcLUe{
XWnVgY s
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) K~uXO
{ 2{D{sa
sSiteURL= sURL; u^&A W$
sFilePath = sPath; }~2LW" 1'
sFileName = sName; 6e(Qwt
this.nSplitter = nSpiltter; a@8v^G
&)2i[X
60P<4
} zofa-7'Bn
o\BOL3H
Y1L[;)Hn
public String getSSiteURL() H[m:0eF'5
{ czA5n
return sSiteURL; a Ve'ry
} lvdf^b/ j
Ha(c'\T(\
dW_KU}
public void setSSiteURL(String value) j >Ht@Wi
{ D!@Ciw
sSiteURL = value; -] LY,M
} )(A]Ln4
q6@Lp^f
gK_Ymq5>"M
public String getSFilePath() $>G8_q
{ -O1>|y2rU
return sFilePath; 6O|@xvg
} VdPtPq1
F7 5#*
63^O|y\W8
public void setSFilePath(String value) 8H;t_B
{ -]L6=
sFilePath = value; Ld\R:{M"
} mkMq
Bu#E9hJFvA
%u?>#
public String getSFileName() ;}7Rjl#
{ r/4``shg
return sFileName; c*(bO3 b
} X]'{(?Ch
%;cddLQ\xY
VAWF3
public void setSFileName(String value) ={_C&57N1
{ 0bz'&
sFileName = value; 2!0c4a^z
} mi ik%7>W
(gEBOol
F{Z~ R
public int getNSplitter() 5G::wuxk
{ YT8vP~
return nSplitter; .|hf\1_J
} C+'/>=>a.
mN~ci 0
Z&#('Z
public void setNSplitter(int nCount) J3,fk)
{ |h-QP#]/
nSplitter = nCount; Vc_'hz]Z
} MTsM]o
} Y?S!8-z
6 2'j!"xv
--PtZ]Z
/* _ <WJ7
**Utility.java cFaaLUZk
*/ ?$vCW|f
package NetFox; pczug-nB
&7<TAo;O
1|RANy
public class Utility { EwuO&q
*194{ ep
@<&5J7fb
public Utility() j2ve^F:Q
{ (mgS"zPS
|y&*MTfV4L
Z8zmHc"IH
} ]or>?{4g
cJN7bA{
//线程睡眠 s8wmCzB~
public static void sleep(int nSecond) 61.Brp.eP
{ J!0DR4=Xi
try{ !6BW@GeF]
Thread.sleep(nSecond); #i@;J]x(
} ~R_ztD+C(
catch(Exception e) 0TCBQ~"
{ *i]=f6G
e.printStackTrace (); 1xD=ffM>8N
} WfWN(:dF
} "^4_@ oo
aEM%R<e
//日志 s}j{#xT
public static void log(String sMsg) A9f)tqbc
{ uxW~uEh
System.err.println(sMsg); Q o?O:
} 4xk|F'6K
uv=.2U46
}E0,z
public static void log(int sMsg) {6"Ph(I1
{ eAXc:222
System.err.println(sMsg); \n{qsf:
} <Fi%iA
} MNC*Glj=
x$IX5:E#e
,8:(OB|a
/* i 7_ _
**TestMethod.java ~;1l9^N|
*/ LO <
package NetFox; 7[I}*3Q'
;u;#g
X}tVmO?
public class TestMethod { "]z-: \ V
O$IEn/%+
vg D77
public TestMethod() 99}(~B
{ ///xx/weblogic60b2_win.exe jqv-D
try{ b /@#}Gc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 0o+6Q8q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A3|Dz&@:
SiteFileFetch fileFetch = new SiteFileFetch(bean); '@p['#\uI
fileFetch.start(); zoOaVV&1
} Fe]B&n
catch(Exception e){e.printStackTrace ();} !'mq ?C=
0Uz\H0T1
;k7xMZs
} _h X]%
Z0o~+Ct$
h<Ft_#|o[
public static void main(String[] args) uM_#
{ Z7_m)@%;kk
new TestMethod(); tcLnN:
} Ytz)d/3T
} `0P$#5?
点击下载更多相关资料