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)); }b]z+4Ua(
} <w0$0ku
for(int i=0;i<nEndPos.length-1;i++) 0'II6,:
{ Si=u=FI1e
nEndPos = nStartPos[i+1]; PLQLGb4f_;
} X/<Q3AK
nEndPos[nEndPos.length-1] = nFileLength; X[$FjKZh=F
} QR[i9'`<
} Eh.NJI(
;c0z6E /
f26hB;n
//启动子线程 b,-qyJW6
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; '>dx~v %
for(int i=0;i<nStartPos.length;i++) cp3O$S
{ W< :7z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), s)V<dm;T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (-hGb:
nStartPos,nEndPos,i); L%0G >2x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4 JDk()
fileSplitterFetch.start(); 1zJ)x?
} MI|anM
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), //-;uEO
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Et+WLQ6)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", bv4G!21]*;
nEndPos = " + nFileLength); 6%fF6
// fileSplitterFetch[nPos.length-1].start(); vFl06N2
{_>}K
(@;=[5+
//等待子线程结束 qI5`:PH%n
//int count = 0; rCgoU xW`
//是否结束while循环 J(=io_\bO
boolean breakWhile = false; <~-cp61z;
rnS&^
b=Oec%Adx
while(!bStop) ;n;bap
{ ;TTH
write_nPos(); !5=S2<UX
Utility.sleep(500); PNhxF C.
breakWhile = true; Xi81?F?[
/zZ";4
2(K@V6j$M
for(int i=0;i<nStartPos.length;i++) jP"l5
{ M5T4{^i
if(!fileSplitterFetch.bDownOver) D:vX/mf;7
{ XPsRa[08WK
breakWhile = false; bz\-%$^k
break; J0O wzO
} ud:5_*
} Z@QJ5F1y
if(breakWhile) xdkC>o4>
break; *^Xtorqo
Ue2%w/Yo
_2E*
//count++; hmM2c15T5
//if(count>4) u5E\wRn
// siteStop(); uo[W|Q
} #f-pkeaeq
dxK3462
5><KTya?=
System.err.println("文件下载结束！"); rs+ ["h
} -wrVhCd~g]
catch(Exception e){e.printStackTrace ();} t?;\'
} 9HBRWh6
s?~lMm' !
LMTz/M
//获得文件长度 $fFh4O4
public long getFileSize() K4K]oT
{ tiQeON-Q_
int nFileLength = -1; ^&Wa? m.
try{ bTbF
URL url = new URL(siteInfoBean.getSSiteURL()); o#9Q
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b>x03%
httpConnection.setRequestProperty("User-Agent","NetFox"); crl"Ec
TAp8x
"'v^X!"
int responseCode=httpConnection.getResponseCode(); dBNx2T}_0
if(responseCode>=400) :hFKmoy#
{ RAB'%CY4
processErrorCode(responseCode); Z,1b$:+
return -2; //-2 represent access is error GvI8W)d3,R
} ,4H/>yPw
0AD8X+M{P
%:e.ES
String sHeader; P87Lo4Rd
2wwJ>iR`
*"Uf|
for(int i=1;;i++) FW)VyVFmk
{ pj#ls
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Pmdf:?B
//Utility.log(in.readLine()); d3"QCl
sHeader=httpConnection.getHeaderFieldKey(i); \dJOZ2J<z
if(sHeader!=null) oe<DP7e
{ 9Yd"Y-
if(sHeader.equals("Content-Length")) Wn-'iD+9<
{ s`gfz}/
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,{X}C
break; wDDNB1_E
} t W}"PKv
} b} FhC"'i
else )fQ1U
break; WS//0
} lc\{47LwZ
} i ?PgYk&}
catch(IOException e){e.printStackTrace ();} 0Ua&_D"
catch(Exception e){e.printStackTrace ();} <b:xyHS
V{UY_ e8W
==AmL]*
Utility.log(nFileLength); dngG=
yw1-4*$c
L7]o^p{g}Q
return nFileLength; "x3x$JQZy
} Xo$SQ0K
)H(i)$I
RT|1M"?$
//保存下载信息（文件指针位置） :!Nx'F9a
private void write_nPos() [kf6bf@
{ +ZOKfX
try{ |A\o
output = new DataOutputStream(new FileOutputStream(tmpFile)); +;-ZU
output.writeInt(nStartPos.length); :b] \*
for(int i=0;i<nStartPos.length;i++) G*_qqb{B
{ b]
// output.writeLong(nPos); 09qfnQG
output.writeLong(fileSplitterFetch.nStartPos); YSrjg|k*
output.writeLong(fileSplitterFetch.nEndPos); _F8THYg (
} U(Tl$#Bt
output.close(); aWPf3Q
} j WSgO(y
catch(IOException e){e.printStackTrace ();} " sC]z}
catch(Exception e){e.printStackTrace ();} ?)T@qn+
} yi:}UlO
Fv*Et-8tN5
1R;@v3
//读取保存的下载信息（文件指针位置） &u~Pp=kv
private void read_nPos() W,"Re,`H
{ $6(a6!
try{ ex BLj *]
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); S*gm[ZLQ
int nCount = input.readInt(); N\];{pe>
nStartPos = new long[nCount]; XOLE=zdSp
nEndPos = new long[nCount]; ,Js-'vX
for(int i=0;i<nStartPos.length;i++) o".,JnbXl
{ |]9L#
nStartPos = input.readLong(); ~sZ$`t
nEndPos = input.readLong(); @v#,SF{
} S}a]Bt
input.close(); k>\v]&|T`
} IJt'[&D
catch(IOException e){e.printStackTrace ();} I$MlIz$l v
catch(Exception e){e.printStackTrace ();} Eh)VT{vp
} PfyJJAQ[
z1]nC]2
:Nv7Wt!
private void processErrorCode(int nErrorCode) Oet+$ b
{ vQ]d?Tp
System.err.println("Error Code : " + nErrorCode); wZN_YFwQ
} H\qZu%F'
YCQ$X
PR]b]=
//停止文件下载 e#,(a
public void siteStop() JXMH7
{ .#-F@0a
bStop = true; 46pR!k
for(int i=0;i<nStartPos.length;i++) \=7jp|{Yl
fileSplitterFetch.splitterStop(); 0#DEh|?
.izq}q*P
e0h[(3bXs$
} )UM^#<-
} [8^q3o7n
//负责部分文件的抓取 [61*/=gWe
**FileSplitterFetch.java HFI0\*xn(
*/ w#[cGaIB
package NetFox; !yxqOT-
7KX27.~F
R"9wVM;*c
import java.io.*; \Dy|}LE
import java.net.*; KyfH8Na?
`d$@1
[!yA#{xl,
public class FileSplitterFetch extends Thread { QxdC[t$Lp
w3ni@'X8
{x.0Yh7
String sURL; //File URL J-Tiwl
long nStartPos; //File Snippet Start Position IlB8~{p_
long nEndPos; //File Snippet End Position @qan&?-Y
int nThreadID; //Thread's ID ?q9]H5\
boolean bDownOver = false; //Downing is over L"%SU
boolean bStop = false; //Stop identical |Ia9bg'1U
FileAccessI fileAccessI = null; //File Access interface CDRbYO
uT4|43< G
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Xs2 jR14`
{ (=Cb)/s0
this.sURL = sURL; "mf$E|
this.nStartPos = nStart; #aU!f"SS
this.nEndPos = nEnd; U:C:ugm
nThreadID = id; NeG`D'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 NFZ(*v1U
} f4b9o[,s2e
\agZD+
ur\6~'l4
public void run() LK~aLa5wG
{ , :#bo]3
while(nStartPos < nEndPos && !bStop) )ZpI%M?)
{ mGj)Zrx>
=+Fb\HvX{
PY.K_(D
try{ > 0MP[
URL url = new URL(sURL); o5tCbsHj-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {uaDpRt
httpConnection.setRequestProperty("User-Agent","NetFox"); ,UMr_ e{|
String sProperty = "bytes="+nStartPos+"-"; B/1j4/MS
httpConnection.setRequestProperty("RANGE",sProperty); &,k!,<IF
Utility.log(sProperty); 05q760I+
j#n ]q{s4
ORs:S$Nt$
InputStream input = httpConnection.getInputStream(); 6iyl8uL0J
//logResponseHead(httpConnection); I?3b}#&V9
hpF_@n
~R w1
byte[] b = new byte[1024]; {r&mNbz
int nRead; j2MA['{
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 2{rWAPHgz
{ z3tx]Ade
nStartPos += fileAccessI.write(b,0,nRead); h9H z6 >
//if(nThreadID == 1) $v;WmYTJ
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _Sr7b#)o
} <eG|`
0+FPAqX
Svn7.Ivep
Utility.log("Thread " + nThreadID + " is over!"); )/$J$'mcxd
bDownOver = true; .KA-=$~J1
//nPos = fileAccessI.write (b,0,nRead); STW?0B'Jr
} <T}U 3lL^
catch(Exception e){e.printStackTrace ();} F?Lt-a+
} |u>(~6
} #KJ# 1
JY,$B-l
o8g7wM]M
//打印回应的头信息 Z!"-LQJ
public void logResponseHead(HttpURLConnection con) 6dIPgie3w
{ m^3x%ENZ
for(int i=1;;i++) 5^g*
{ gZ,h95'
String header=con.getHeaderFieldKey(i); 9p W~Gz
if(header!=null) F/s n"2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); H -Mb:4
Utility.log(header+" : "+con.getHeaderField(header)); P8z%*/ 3NF
else J?8Mo=UZz
break; @|b-X? `
} f*o
} ks#3 o+
zC2:c"E I
)zr*Ecz
public void splitterStop() =0ZRGp
{ BDI|z/~&
bStop = true; E!9WZY
} HOP*QX8C%
A& iv
xe!bfzU
} :wC\IwG~CE
7iP+!e}$.
uHgq"e
/* ybBmg'198
**FileAccess.java M=^d
*//文件访问(定位，写) X4V>qHV72
package NetFox; +S4n416K
import java.io.*; i>Q!5
DDeU:
/$c87\
public class FileAccessI implements Serializable{ b#_RZ
xi5"?*&Sb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 U^dfNi@q
RandomAccessFile oSavedFile; ]fM|cN8(zM
long nPos; E5ce=$o
= lo.LFV
'ITq\1z
public FileAccessI() throws IOException 2%%\jlT_
{ K[z)ts-
this("",0); sINQ?4_8T
} |:eTo<
nTy]sPn
IoDT
public FileAccessI(String sName,long nPos) throws IOException =-U0r$sK+F
{ b80#75Bj>
oSavedFile = new RandomAccessFile(sName,"rw"); enQ*uMKd^
this.nPos = nPos; E%mEfj7
oSavedFile.seek(nPos); x92^0cMf
} EvT$|#FY
|v!N1+v0
(]]hSkE
public synchronized int write(byte[] b,int nStart,int nLen) p@tg pFt
{ ?bZH Aed
int n = -1; u$T]A8e
try{ )3h\QE!z
oSavedFile.write(b,nStart,nLen); BSm"]!D8*
n = nLen; a-NTA
} tV)CDA&Z
catch(IOException e) !T0I; j&
{ }A3/(
e.printStackTrace (); 9j2t|D4uT
} &L8RLSfX
s=8H<'l
H*W>v[>
return n; @| z _&E
} 6 U.Jaai:
z CLaHx!
FV^jCseZ
} \|HtE(uCM1
)9eIo&Nl
:kgh~mx5LF
/* 3aqH!?rVU
**SiteInfoBean.java Q|_F P:
*/ :c*"Dx'D
package NetFox; zD{]3pg
Ln>!4i+-B)
&da=hc,>%
public class SiteInfoBean { u&zY>'}zm
alb3oipOB
'kd}vq#|
private String sSiteURL; //Site's URL w"R<8e=
private String sFilePath; //Saved File's Path Rta}*
private String sFileName; //Saved File's Name 3%POTAw%
private int nSplitter; //Count of Splited Downloading File "| '~y}v_
-@N-i$!;J
!#0)`4O
public SiteInfoBean() #T)Gkc"{
{//nSplitter的缺省值为5 o5Oig
//default value of nSplitter is 5 !f~a3 {;j
this("","","",5); I\)`,w
} Myc-lCE
RC_Pj)
8Ths"zwn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) WDc[+Xyw
{ Y:\msq1xp
sSiteURL= sURL; LW1 4 'A}
sFilePath = sPath; s<k[<
sFileName = sName; FvsVfV U
this.nSplitter = nSpiltter; k{*EoV[.$
4%0s p
uaIAVBRcS
} u&~Xgq5[
.tRm1&Qi
f`qy~M&
public String getSSiteURL() |V34;}\4
{ ,hzRqFg2
return sSiteURL; Iy)1(upM
} !S?Fz]
W|<c[S
Qa2h#0j
public void setSSiteURL(String value) I_1?J* b4k
{ dDS{XR
sSiteURL = value; uEgR>X>
} u|<?mA!
u7e$Mq
czRBuo+k+
public String getSFilePath() INndTF
{ 19fa7E<
return sFilePath; [Qs`@u<%
} Zfs-M)
;0eVE
~~yng-3)1
public void setSFilePath(String value) hWly8B[I
{ CaYb}.:AX
sFilePath = value; |lhnCShw
} HxbzFu?h
..yV=idI
.vHHw@
public String getSFileName() 5 3pW:`
{ :>!-[hfQ
return sFileName; q0WW^jwQ
} *ggTTHy
xVoWGz7
J#Fe"
public void setSFileName(String value) }]vj"!?a
{ iHjo3_g)n
sFileName = value; Hxr2Q]c?u
} l|`FW
XuJwZN!(
5_Yv>tx
public int getNSplitter() BOJh-(>I
{ O<4i)Lx2
return nSplitter; ezTu1-m
} 1_:1cF{w
UwtOlV:G{
Bp\io$(%
public void setNSplitter(int nCount) C>cc!+n%H
{ R#~}ZUk2
nSplitter = nCount; G B!3` A%&
} 7HPLD&WPt
} ,4j$kR
VL5kjF3/
=f@O~nGm
/* tYIHsm\b
**Utility.java #%VprcEK
*/ (PGmA>BT
package NetFox; (Br$(XJoK}
`.;7O27A^%
cb&y8!ci~
public class Utility { t )Z2"_5
]SrKe-*:U
[e)81yZG>
public Utility() :w_F<2d0 0
{ !boKrSw
9CJUOB>]
Af=%5%
} cNC\w%
.Q"3[
//线程睡眠 OdQ>h$ gZ
public static void sleep(int nSecond) o0-e,F>u
{ XBhWj\`(T
try{ QOuy(GY
Thread.sleep(nSecond); bI[!y#_z4
} N-^\X3X
catch(Exception e) /iif@5lw{
{ +Smv<^bW
e.printStackTrace (); |}Mkn4
} w GZ(bKyO
} X1<)B]y
:'y
//日志 ZC"6B(d
public static void log(String sMsg) %fP^Fh
{ :EgdV
System.err.println(sMsg); CW\o>yh
} /p\Ymq
=@pm-rI|-
R,Zuy(g
public static void log(int sMsg) hD<z^j+
{ ?d+B]VYw
System.err.println(sMsg); 6?*iIA$b
} ]p'Qk
} N["c*=x
ZfT%EPoZ:
-Qnnzp$]
/* yfTnj:Fz
**TestMethod.java n_Um)GI>
*/ u;J=g
package NetFox; \(T;@r
:#TJ-l:#
0O-p(L=
public class TestMethod { 9Z*`{
R5]R pW=G
%h|z)
public TestMethod() #PXl*~PrQ/
{ ///xx/weblogic60b2_win.exe 4L!{U@'
try{ IUd>jHp`6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ItM?nyA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /bCrpcH
SiteFileFetch fileFetch = new SiteFileFetch(bean); YD@V2gK
fileFetch.start(); rA=F:N 2
} 1<\cMY6
catch(Exception e){e.printStackTrace ();} p00\C
ac+7D:X
+Yi=Wo/
} oeIB1DaI
XQj`KUO@
5\|[)~b
public static void main(String[] args) YY7:WQS
{ !&Q,]\j
new TestMethod(); AL|fL
} Fg#*rzA
} 0RoI`>j'
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