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)); t:)ERT")
} e<cM[6H'D
for(int i=0;i<nEndPos.length-1;i++) j Ux z
{ +>\id~c(
nEndPos = nStartPos[i+1]; }H"kU2l
} eE@&ze>X
nEndPos[nEndPos.length-1] = nFileLength; }4//@J?:
} fo0+dzazY
} Qk1xUE
hA1-){aw3q
&ldBv_
//启动子线程 8|%^3O 0X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 8}s.Fg@tE
for(int i=0;i<nStartPos.length;i++) Qf$|_&|
{ 7U|mu~$.!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n$n7-7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,yd=e}lQx
nStartPos,nEndPos,i); _zWfI.o
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); T0zn,ej
fileSplitterFetch.start(); De&6 9
} .iD*>M:W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 36.N>G,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); JW.=T)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9f+>ix,ek*
nEndPos = " + nFileLength); D BE4&
// fileSplitterFetch[nPos.length-1].start(); 4m)OR
jPZaD>!
c%m3}mrb
//等待子线程结束 U.!lTLjfLz
//int count = 0; !> }.~[M
//是否结束while循环 ~{,X3-S_H
boolean breakWhile = false; 6/V3.UP-
\p{5D`HY
e]=lKxFh&l
while(!bStop) e[_m<e
{ qMt++*Ls
write_nPos(); R:Q0=PzDi#
Utility.sleep(500); YH&bD16c3
breakWhile = true; 9o*,P,j'}
DwHF[]v'
,Uhb
for(int i=0;i<nStartPos.length;i++) N- H^lqD
{ l 'DsZ9y@2
if(!fileSplitterFetch.bDownOver) 3"n\8#X{
{ ,L bBpi=TJ
breakWhile = false; +l3=3
break; . \
} 10!wqyj&
} X4l@woh%
if(breakWhile) ';Zi@f"
break; ~vlype3/EF
?;/^Ya1;Z
$Iv2j">3)
//count++; evkH05+;W
//if(count>4) Tou/5?#%e
// siteStop(); ]$b[`g&
} l7#yZ*<v
6`vC1PK^
!$N<ds.
System.err.println("文件下载结束！"); EnOU?D
} 9$`lIy@B
catch(Exception e){e.printStackTrace ();} AL#4_]m'
} _4^R9Bt
l2N]a9bq@
^P151*=D
//获得文件长度 nWQ;9_qBB
public long getFileSize() ;qHOOT
{ `W/sP\3
int nFileLength = -1; r'QnX;99T
try{ 7$h#OV*@,
URL url = new URL(siteInfoBean.getSSiteURL()); V,rq0xW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3gd&i
httpConnection.setRequestProperty("User-Agent","NetFox"); oy<WsbnS
-'~LjA(
_uc hU=
int responseCode=httpConnection.getResponseCode(); 2^i(gaXUQ
if(responseCode>=400) g1t0l%_7^
{ y WV#Up
processErrorCode(responseCode); AL>$HB$
return -2; //-2 represent access is error P#=`2a#G
} 23~Sjr
Aq3}Ng
5^^XQ?"
String sHeader; mZd , 9
Kq i4hK
r@ZJ{4\Q
for(int i=1;;i++) u\eEh*<7q
{ M|:UwqV>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Yw#2uh
//Utility.log(in.readLine()); tHzZ@72B7
sHeader=httpConnection.getHeaderFieldKey(i); Qxj JN^Q
if(sHeader!=null) M(/r%-D
{ [jmd
if(sHeader.equals("Content-Length")) r Tz$^a}/
{ OpHsob~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C*P7-oE2rh
break; B(M6@1m_
} ..rOsg{
} 0jEL<TgC
else n=[/Z!
break; Yk=PS[f
} "I(xgx*
} i':C)7
catch(IOException e){e.printStackTrace ();} cTG|fdgMW
catch(Exception e){e.printStackTrace ();} IIbYfPiO
h<$MyN4]g
i[ mEi|
Utility.log(nFileLength); w K}T`*k
thhwN A
Dc,I7F|%
return nFileLength; ~ 0M'7q'
} P-9<YN
%$b:X5$Z
z*-2.}&U<
//保存下载信息（文件指针位置） %f]:I
private void write_nPos() <_7*67{
{ P'_H/r/#
try{ 0\eIQp
output = new DataOutputStream(new FileOutputStream(tmpFile)); wp&=$Aa)'
output.writeInt(nStartPos.length); I1X-s
for(int i=0;i<nStartPos.length;i++) EKO[!,
{ 13>0OKg`#
// output.writeLong(nPos); UeRj< \"Q
output.writeLong(fileSplitterFetch.nStartPos); D|{jR~J)xK
output.writeLong(fileSplitterFetch.nEndPos); HPZ}*m'
} Ftr5k^!
output.close(); ')$+G152
} 4qk9NK2 U
catch(IOException e){e.printStackTrace ();} 9gmW&{6q
catch(Exception e){e.printStackTrace ();} !_Wi!Vr_
} &wV]"&-
K57&yVX
qw^uPs7Uw
//读取保存的下载信息（文件指针位置） adR)Uq9
private void read_nPos() 3xaR@xjS
{ h5^Z2:#
try{ ,LnII
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w9bbMx
int nCount = input.readInt(); ;<ZLcTL
nStartPos = new long[nCount]; S Em Q@1
nEndPos = new long[nCount]; |AozR ~
for(int i=0;i<nStartPos.length;i++) N(Tz%o4
{ 2%_vXo=I
nStartPos = input.readLong(); WHj'dodS
nEndPos = input.readLong(); tIuCct-
} .?loO3 m
input.close(); :s7m4!EF
} \hx1o\
catch(IOException e){e.printStackTrace ();} &__es{;P
catch(Exception e){e.printStackTrace ();} r/u A.Aou^
} y#3j`. $3p
?k(7 LX0j
`)_dS&_\
private void processErrorCode(int nErrorCode) r2,.abo
{ N(Fp0
System.err.println("Error Code : " + nErrorCode); Tu).K.p:
} AHXSt
LhA/xf
pu2tY7Ja
//停止文件下载 )mF5Vw"
public void siteStop() @}}$zv6l,
{ 8; 0A g
bStop = true; e?8HgiP-
for(int i=0;i<nStartPos.length;i++) '/^qJ7eb
fileSplitterFetch.splitterStop(); $\X[@E S0
J4fi'
,[P{HrHx
} hpO`]
} [PNT\ElT
//负责部分文件的抓取 ?#}N1k\S
**FileSplitterFetch.java SAy=WV
*/ e&&53?
package NetFox; BRgXr
JvVWG'Z"
cj$[E]B3V*
import java.io.*; UG+d-&~Ll
import java.net.*; 5kCUaPu
1;Ou7T9w
tMf}
public class FileSplitterFetch extends Thread { MkfBuW;)
>n'o*gZM
"@iK' c^
String sURL; //File URL >7jbgHB
long nStartPos; //File Snippet Start Position (|klSz_4LM
long nEndPos; //File Snippet End Position #49kjv@
int nThreadID; //Thread's ID u{['<r;I
boolean bDownOver = false; //Downing is over l]Ax:Z
boolean bStop = false; //Stop identical /5(Yy}
FileAccessI fileAccessI = null; //File Access interface ywGd>@
F\KjEl0
jB%lB1Q|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q(wx nm
{ a_f~N1kq
this.sURL = sURL; 49GkPy#]L=
this.nStartPos = nStart; (^TF%(H
this.nEndPos = nEnd; :XZU&Sr"
nThreadID = id; ,(qRc(Ho
fileAccessI = new FileAccessI(sName,nStartPos);//定位 lr>oYS0
} m% -g~q
0D\#Pq v
oM2l-[-
public void run() 7}f}$1
{ v$7QIl_/7
while(nStartPos < nEndPos && !bStop) $q6BP'7
{ %b&".mN
{o_X`rgrL
JEXy%hl
try{ vQosPS_2L
URL url = new URL(sURL); G&D7a/G\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -]/I73!b
httpConnection.setRequestProperty("User-Agent","NetFox"); `Q|*1
String sProperty = "bytes="+nStartPos+"-"; #hfXZVD
httpConnection.setRequestProperty("RANGE",sProperty); >7lx=T x
Utility.log(sProperty); -lbm* -(
_<k\FU r
7Ri46Tkt
InputStream input = httpConnection.getInputStream(); [ey:e6,T9
//logResponseHead(httpConnection); nKPYOY8^
}Lc-7[/
7X0Lq}G@
byte[] b = new byte[1024]; ;&<{ey
int nRead; 5]KW^sL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) E7t+E)=8
{ Y2a5bc P
nStartPos += fileAccessI.write(b,0,nRead); lD)%s!
//if(nThreadID == 1) 6h|q'.Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); LPZF)@|`
} nygbt<;?
*W.C7=
C7rNV0.Fq
Utility.log("Thread " + nThreadID + " is over!"); U{7w#>V .
bDownOver = true; @Z*W
//nPos = fileAccessI.write (b,0,nRead); `|6'9
} iq8GrdL"
catch(Exception e){e.printStackTrace ();} u[@l~gwL
} +]*zlE\N`
} S=5<^o^h3
`z{%(_+[
p`b"-[93
//打印回应的头信息 wT;0w3.Z
public void logResponseHead(HttpURLConnection con) N >FKy'.gk
{ !TAlBkj
for(int i=1;;i++) f%SZg!+t
{ [b6R%
String header=con.getHeaderFieldKey(i); 0"kbrv2y
if(header!=null) XRcqhv
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {_7i8c<s=
Utility.log(header+" : "+con.getHeaderField(header)); ?3nR
else 6g|*`x{
break; d ^^bke$~
} GGNvu)"
} BzkooJ
3L<wQ(
7op`s5i
public void splitterStop() E)TN,@%
{ 6VS4y-N
bStop = true; wP6Fl L
} QN #U)wn:
J3e96t~u
N*"p|yhd]
} s%qF/70'
tX5"UQA
g l^<Q
/* gW^VVbB'L
**FileAccess.java Yk)."r&?
*//文件访问(定位，写) UYk/v]ZA
package NetFox; K?[q%W]%
import java.io.*; xDG2ws=@D
+fC=UAZ
)k\H@Dy%$
public class FileAccessI implements Serializable{ Z3#P,y9@
U}6B*Xx'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6ys &zy
RandomAccessFile oSavedFile; iI\oz&!vH
long nPos; gnFr}L&j
C9~52+S
",^Mxm{
public FileAccessI() throws IOException kqM045W7
{ s"0Y3x3
this("",0); !F1M(zFD
} R@/"B8H
5 xppKt
6N",-c
public FileAccessI(String sName,long nPos) throws IOException |%J{RA
{ -7*ET3NSI/
oSavedFile = new RandomAccessFile(sName,"rw"); v/](yT
this.nPos = nPos; [Yo,*,y31
oSavedFile.seek(nPos); brW :C?}
} 3?c3<`TW
5k`l$mW{
%6t2ohO"
public synchronized int write(byte[] b,int nStart,int nLen) T;L>;E>B
{ (MR_^t
int n = -1; zfc'=ODX
try{ SW*"\X;
oSavedFile.write(b,nStart,nLen); : ]sUpO
n = nLen; $K]m{
} Z1 Bp+a3
catch(IOException e) 6A>dhU
{ 3 ^>l\,
e.printStackTrace (); <QA6/Ef7
} R$q; !
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pk^K:Xs}
return n; CS@FYO
} {_`^R>"\&w
23c 8
M[mF8Zf
} Ont%eC\
`}(b2Hc>
Jz7!4mu
/* e8pG"`wM8
**SiteInfoBean.java F ~^Jmp7Y
*/ `V`lo,"\
package NetFox; ht2\y&si
AfX}y+Ah
,quoRan
public class SiteInfoBean { L;*ljZ^c
|.F$G<
\MbB#
private String sSiteURL; //Site's URL eM$sv9?
private String sFilePath; //Saved File's Path [Jogt#Fj ]
private String sFileName; //Saved File's Name l5zS
private int nSplitter; //Count of Splited Downloading File *A"~m!=
{U1?Et#
Oy%''+g
public SiteInfoBean() M-1ngI0H;
{//nSplitter的缺省值为5 fz\9 S
//default value of nSplitter is 5 (Dw,DY9
this("","","",5); [<%H>S1
} bmfI~8
' 0J1vG~c
g]4(g<:O
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) qAn!RkA
{ pi Z[Y 5OE
sSiteURL= sURL; MCS8y+QK
sFilePath = sPath; ;D:9+E<>a
sFileName = sName; @)|C/oA
this.nSplitter = nSpiltter; EB2w0a5
4)@mSSfn.
WU quN
} X$ s:>[H
K POa|$
SZ,YS 4M
public String getSSiteURL() -=~| ."O
{ ~$)2s7 O
return sSiteURL; Pb1*\+
} VFRi1\G
"JlpU-8[0@
sE:M@`2L
public void setSSiteURL(String value) `%+Wz0(K
{ g/P+ZXJ
sSiteURL = value; -(
} bYEy<7)x
3~uW I%I`
GT0Of~?f
public String getSFilePath() P*FMwrJj>r
{ Fs9I7~L3
return sFilePath; "uaMk}[ <!
} nm6h%}xND<
~]nSSD)\
;1%-8f:lW
public void setSFilePath(String value) W3MU1gl6k{
{ wE?'Cl
sFilePath = value; KwPOO{4]g
} B"!l2
a-=8xs'
^pQCNKLBY
public String getSFileName() y#U+c*LB
{ D;;!ODX$?
return sFileName; gBC@38|6)
} gk"$,\DI
c_vqL$Dl
cc~O&?)i
public void setSFileName(String value) n=y[CKS
{ %-c*C$
sFileName = value; hw= Ft4L
} 3HcQ(+Z
nlW +.a[
7ccO93Mz
public int getNSplitter() 7Rd'm'l)
{ {bJ`~b9e
return nSplitter; "nw;NIp!
} b[o"7^H
6YGubH7%_
6]W=nAD
public void setNSplitter(int nCount) BYVY)<v/
{ q,93nhs "
nSplitter = nCount; *X+79vG:
} }a/x._[s
} J&.{7YF
?4q4J8j
Qo;zHZ'
/* VJickXA
**Utility.java {<R2UI5m5
*/ 8,?h~prc
package NetFox; {q`jDDM
+yk24 `>
g*03{l#P
public class Utility { inh=WUEW
apg=-^L'
HY&aV2|A1
public Utility() A8uVK5
{ M%2+y5
e?JW
1~Oe=`{&
} `w.n]TR
_"bHe/'CI
//线程睡眠 &jslyQ#
public static void sleep(int nSecond) amOnqH-(
{ 7UVzp v
try{ KH(%?
Thread.sleep(nSecond); 2jR r,Nl
} /OLFcxEWh
catch(Exception e) cx&>#8s&
{ lku[dQdk
e.printStackTrace (); Ye2 {f"F
} _AAaC_q
} !g5xq
VUPXO
//日志 "alyfyBu'M
public static void log(String sMsg) x4;"!Kq\
{ ?[g=F <r
System.err.println(sMsg); y(CS5v#FG
} {khqu:HUn`
5,_u/5Y4
YQHw1
public static void log(int sMsg) }<@b=_>S
{ WD]pU
System.err.println(sMsg); oSyyd
} o0ifp=V y
} ADDSCY=,
ts\5uiB<%
MZSy6v
/* \;qW 3~
**TestMethod.java Z>)Bp/-
*/ X*/ho
package NetFox; f&BY/ n,
Fl kcU `j
9 7GV2]-M
public class TestMethod { =t9\^RIx)?
'gC_)rK*
/fZeWU0W
public TestMethod() jcuB
{ ///xx/weblogic60b2_win.exe ^l9N48]|?
try{ 9 Vkb>yFX'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 95 ;x=ju
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); B@&4i?yJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); o]yl;I
fileFetch.start(); QZ6D7tUc8
} nuk*.Su
catch(Exception e){e.printStackTrace ();} =Xi07_8Ic<
3Dng1}
:~2vJzp@?
} 2%LLSa
YB(Q\hT~\;
p1Jh0o8
public static void main(String[] args) b\yXbyjZ3.
{ 06O2:5zF
new TestMethod(); Q.l}NtHwV
} uJzG|$;
} @;*Ksy@1O
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