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)); 2u#{K9g
} #YhKAG@|
for(int i=0;i<nEndPos.length-1;i++) QWfwoe&;R:
{ F~<$E*&h@
nEndPos = nStartPos[i+1]; Gvj@?62
} 7|"11^q
nEndPos[nEndPos.length-1] = nFileLength; pE15[fJ`
} C^l)n!fq
} *4=Fy:R]O
+h*&r~T
pOw4H67
//启动子线程 :i?Z1x1`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b!_l(2
for(int i=0;i<nStartPos.length;i++) 'pZ~3q
{ qdUlT*fw
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9lOUE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), %Sxy!gGz%%
nStartPos,nEndPos,i); =a7m^e7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <6-(a;T!7
fileSplitterFetch.start(); PMkwY{.u
} RwT.B+Onuy
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I>G)wRpfR'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); r}03&h~Hc&
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 9.PY49|
nEndPos = " + nFileLength); 9-pd{Z~l
// fileSplitterFetch[nPos.length-1].start(); ~+^,o_hT
7Zr jU{
KasOh"W.P
//等待子线程结束 v mw7H
//int count = 0; xAz gQ
//是否结束while循环 ^!Bpev
boolean breakWhile = false; x{Gih1
eYR/kZ%<
$#"}g#u
while(!bStop) LhV4 ^\+
{ 8v(Xr}q,r
write_nPos(); "B)DX*-\?
Utility.sleep(500); BWw7o{d
breakWhile = true; cDE?Xo'!
TSE(Kt
QF-.")Z
for(int i=0;i<nStartPos.length;i++) `1pri0!
{ .8.ivfmJh
if(!fileSplitterFetch.bDownOver) %;^6W7
{ Bg7?1m
breakWhile = false; .%~ L
break; r+$ 0u~^
} I|iI ,l/9
} MV=.(Zs
if(breakWhile) Fi*6ud\n!
break; EEaKT`/d
/Tv< l
li NPXS+
//count++; ]1D>3
//if(count>4) 4p %`Lv
// siteStop(); `.[hOQ7
} vs6`oW"{#
7B7I'{d
mc9$"
System.err.println("文件下载结束！"); 3PBg3Y$
} nC>#@*+jK
catch(Exception e){e.printStackTrace ();} V @d:n
} ~{+J~5!;<H
p'xj:bB
;Oe6SNquT
//获得文件长度 :i:Zc~%
public long getFileSize() h"ZF,g;a
{ \6C"bQ
int nFileLength = -1; !kmo%+
try{ Y]P $|JW):
URL url = new URL(siteInfoBean.getSSiteURL()); frGUT#9?n
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I`5MAvP
httpConnection.setRequestProperty("User-Agent","NetFox"); qZ8lU
I<[(hPQUf
<_42h|-
int responseCode=httpConnection.getResponseCode(); ZO0_:T#Z
if(responseCode>=400) |mci-ZT
{ qD`')=
processErrorCode(responseCode); (y(V,kXwa8
return -2; //-2 represent access is error guFR5>-L
} QW~o+N~~
-U;s,>\)
gvwR16N
String sHeader; gB kb0
Q[~O`Lz
@?gH3Y_
for(int i=1;;i++) 'n>|jw)
{ G%'h'AV"
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7a@V2cr@
//Utility.log(in.readLine()); urtcSq&H'
sHeader=httpConnection.getHeaderFieldKey(i); gb@!Co3
if(sHeader!=null) ?w<x_Lo
{ u# %7>=
if(sHeader.equals("Content-Length")) #*Mk@XrV
{ 6E_YQbdy
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R` X$@iM
break; X)nOY*
} qTffh{q V
} <v5toyA
else /Ee0S8!Z!1
break; KP:O]520
} e3(0L I
} UejG$JyHP
catch(IOException e){e.printStackTrace ();} u2Rmp4]
catch(Exception e){e.printStackTrace ();} MJ92S(
;$|+H"g|
TOBAh.1
Utility.log(nFileLength); t^h>~o'\
3QXGbu}:h!
pw(`+x]
return nFileLength; 8#kFS@
} Nwu#,f=X
? 4.W _
6qHo$#iT
//保存下载信息（文件指针位置） qrt+{5/t
private void write_nPos() VQ}=7oe%q
{ kSI,Q!e\
try{ I7[+:?2
output = new DataOutputStream(new FileOutputStream(tmpFile)); @${!C$[1
output.writeInt(nStartPos.length); c)Y I3G$
for(int i=0;i<nStartPos.length;i++) pwu5Fxn)
{ %!eK"DKG^
// output.writeLong(nPos); 5Impv3qaZ
output.writeLong(fileSplitterFetch.nStartPos); _~_Hup
output.writeLong(fileSplitterFetch.nEndPos); nQ/ha9v=n
} g`1*p|
output.close(); u\Xi]pZ@X]
} M8g=t[\
catch(IOException e){e.printStackTrace ();} *, {b]6v
catch(Exception e){e.printStackTrace ();} J@R+t6$3O
} 1p{\jCi,2
bBDgyFSI<
nbOMtK
//读取保存的下载信息（文件指针位置） (jQL?
private void read_nPos() 8, WQ}cC
{ ?.,cWKGQ}
try{ x^C,xP[#Y;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); "3$@
int nCount = input.readInt(); 1x\%VtO>\b
nStartPos = new long[nCount]; KIuYWr7&
nEndPos = new long[nCount]; Ii4Byyfx
for(int i=0;i<nStartPos.length;i++) 73]%^kx=
{ 6*]Kow?
nStartPos = input.readLong(); u`("x5sa
nEndPos = input.readLong(); Xbap'/t
} vKI,|UD&-
input.close(); _@d.wfM
} m=opY~&h
catch(IOException e){e.printStackTrace ();} 9g 2x+@5T^
catch(Exception e){e.printStackTrace ();} 1`h`-dqr#
} (xxJ^u>QC
P~]BB.tog
~(yh0V
private void processErrorCode(int nErrorCode) w|RG
{ 6}|/~n
System.err.println("Error Code : " + nErrorCode); x9@%L{*
} (zTr/
j)J4[j
r_R|.fl<[
//停止文件下载 ,@[Q:fY
public void siteStop() H:0-.a^ZS
{ ^]Gt<_
bStop = true; wRLkO/Fw
for(int i=0;i<nStartPos.length;i++) f\|33)k
fileSplitterFetch.splitterStop(); e[{LNM{/#
Z\@vN[[
Ar>Om!]=v
} SYl:X
} }3vB_0[r
//负责部分文件的抓取 2-{8+*_'
**FileSplitterFetch.java fHwh6|
*/ g]d@X_ &D
package NetFox; E!ZDqq
kQ4%J,7e4
ayC*n'
import java.io.*; N7Ne
import java.net.*; OlV>zam
)Hw;{5p@
T0aK1Lh
public class FileSplitterFetch extends Thread { qQVqS7 t
3>?ip;
F,4Q
String sURL; //File URL vwP516EM
long nStartPos; //File Snippet Start Position 8xL-j2w
long nEndPos; //File Snippet End Position >~XX'}
int nThreadID; //Thread's ID )zr/9aV
boolean bDownOver = false; //Downing is over y.mojx%?a
boolean bStop = false; //Stop identical W.H_G.C%
FileAccessI fileAccessI = null; //File Access interface T@k&YJ
spFsrB
[0_Kz"|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s{A-K5S
{ zW+Y{^hf
this.sURL = sURL; [[TB.'k
this.nStartPos = nStart; 3,iL#_+t
this.nEndPos = nEnd; ~r|.GY
nThreadID = id; pz-`Tp w
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,j2qY'wi
} f'r/Q2{n
/\Q{i#v
WhK?>u
public void run() ztb2Ign<
{ ,Hp9Gkm8I/
while(nStartPos < nEndPos && !bStop) gR1X@j$_
{ y)/d-
hW/*]7AM^
)\^%w9h
try{ ]kKf4SJZFU
URL url = new URL(sURL); 9>zN27
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @#o$~'my
httpConnection.setRequestProperty("User-Agent","NetFox"); 5X~ko>
String sProperty = "bytes="+nStartPos+"-"; /mr&Y}7T
httpConnection.setRequestProperty("RANGE",sProperty); FeCQGT
Utility.log(sProperty); xaSkn
-3KB:K<
6"%[s@C
InputStream input = httpConnection.getInputStream(); R[#5E|` `9
//logResponseHead(httpConnection); ;z%& 3u/
iY(hGlV
/=Xen mmS
byte[] b = new byte[1024]; ((X"D/F]
int nRead; /$q;-/DnTZ
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) uj8]\MY
{ hefV0)4K
nStartPos += fileAccessI.write(b,0,nRead); TF3Tha]
//if(nThreadID == 1) 5^%^8o
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H) (K
} O;,k~
)bcMKZ
cHR}`U$
Utility.log("Thread " + nThreadID + " is over!"); <[pU rJfTr
bDownOver = true; FtF!Dtv
//nPos = fileAccessI.write (b,0,nRead); 0@xuxm/i
} %:oGyV7a
catch(Exception e){e.printStackTrace ();} :I&iDS>u1
} ] c'owj
} T!;<Fy"p
+)7NWR\
+{#BQbx6
//打印回应的头信息 W]y$6P
public void logResponseHead(HttpURLConnection con) WMI/Y9N
{ zu;Yw=cM)
for(int i=1;;i++) iP_rEi*-J
{ E!Ng=}G&_
String header=con.getHeaderFieldKey(i); Je?V']lm
if(header!=null) xw?G?(WO
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Gn_v}31d%
Utility.log(header+" : "+con.getHeaderField(header)); \64(`6>
else 7l:H~"9r
break; xK_$^c.
} a%-Yl%#
} C8n1j2G\
GZ4{<QG
cb UVeh7Q
public void splitterStop() 0,/[r/=jT
{ Q!|71{5U
bStop = true; C6,Bqlio
} .y'OoDe
/\\C&Px
7tr.&A^c
} _ !Ph1
2C-RoZ~
$iF7hyZ
/* 1yE~#KpH
**FileAccess.java =]Ek12.
*//文件访问(定位，写) U O[p
package NetFox; C3memimN
import java.io.*; [S9nF
.^v7LF]Q
as\V, {<
public class FileAccessI implements Serializable{ [hiOFmMJZ-
:Z+(H+lyZ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "n05y}
RandomAccessFile oSavedFile; SD697L9
long nPos; z?i82B[Tm
nF//y}
',CcLN
public FileAccessI() throws IOException Ao]F_hZ
{ N.2rF
this("",0); B$lbp03z
} >MhkNy
&MKv_
OrRve$U*|
public FileAccessI(String sName,long nPos) throws IOException c''!&;[!
{ O=+C Kx@
oSavedFile = new RandomAccessFile(sName,"rw"); t Y^:C[
this.nPos = nPos; =!{dKz-&
oSavedFile.seek(nPos); P|6m%y
} T$q]iSgu
#G\)ZheG
,qr)}s-
public synchronized int write(byte[] b,int nStart,int nLen) WFh!re%Z
{ ao,LP,_
int n = -1; c(eu[vj:
try{ _]Hn:O"o
oSavedFile.write(b,nStart,nLen); %b_zUFHPp
n = nLen; }ShZ4 xMz
} sB"]R%`_
catch(IOException e) 8,H
{ U}{r.MryFG
e.printStackTrace (); 00$W>Gr
} [qb#>P2G3
dFS+O;zE\
DLz~$TF^
return n; G.BqT\ o'
} 5ax/jd~}
LOOv8'%O8
!u=[/>
} _-h3>.;h9
RLIugz{IH
M9iu#6P
/* {j(,Q qB;f
**SiteInfoBean.java 9x:c"S*
*/ ,iHl;3bu
package NetFox; 0phGn+"R
S3n$
;,F}!R
public class SiteInfoBean { 0{jRXa-(
#kxg|G[Ol
iveWau292
private String sSiteURL; //Site's URL w1.KRe{M
private String sFilePath; //Saved File's Path W;o\}irep
private String sFileName; //Saved File's Name ~xA'-N/
private int nSplitter; //Count of Splited Downloading File e0aeiG$/0
Iw48+krm>
^6obxwVG
public SiteInfoBean() j:fL_1m
{//nSplitter的缺省值为5 +p_SKk!%+
//default value of nSplitter is 5 Z*leEwgz
this("","","",5); 7?F0~[eGG
} ./[t'dgC
Gm_Cq2PD(
=>ignoeI
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9GCxF`OB
{ rH & ^SNc
sSiteURL= sURL; fv}h;?C
sFilePath = sPath; Wb^YqqE
sFileName = sName; 0;]tC\D1
this.nSplitter = nSpiltter; "Z#&A
!K3 #4
x! Z|^q
} ;ML21OjgN
W4X=.vr
L0Xb^vx}m
public String getSSiteURL() M$|^?U>cm
{ #knpZ'
return sSiteURL; &;*jMu6
} vJK0>":G
yn`H}@`k
-3F|)qwK
public void setSSiteURL(String value) ;}1*M !
{ bT0CQ_g21
sSiteURL = value; +Z/Pj_.o
} >u~ l_?
U^:+J-z{
]B\H
public String getSFilePath() 1VH7z
{ f)/Yru. ;
return sFilePath; ^jqQG+`?
} 1iig0l6\m
5Z1b9.;.,
R$_#7>3
public void setSFilePath(String value) %^kBcId
{ x^xlH!Sc
sFilePath = value; NRgNh5/
} M qFuZg
~*ST fyFw
(TgLCT[@T
public String getSFileName() Gdb6 U{
{ MB%yC]w8
return sFileName; tp7cc;0
} Hj2E-RwG
.T#h5[S2x
&,JrhMr\
public void setSFileName(String value) XE6sFU
{ f#FAi3
sFileName = value; Mj2`p#5wKh
} o]u,<bM$
4l_!OUvt
Pp#
public int getNSplitter() j0_)DG
{ RoS&oGYqR
return nSplitter; vtk0 j
} R6v~Sy&n!
z10J8Ms'
avxr|uk
public void setNSplitter(int nCount) bvzNur_
{ Qu"zzb"k
nSplitter = nCount; oG{0{%*@
} @{n"/6t
} z0!k
>BFUts%
~XU%_Hz
/* "{>BP$Jz
**Utility.java FabgJu
*/ PuO5@SP~
package NetFox; s3<gq x-&r
7n}$|h5D
`X)y5*##wq
public class Utility { %JoHc?
BRSIg]
>L4q>S^v
public Utility() wB'GV1|jL
{ ~xPU#m<
`-Y8T\
f(S9>c2
} 7C / ^Gw
f^Io:V\
//线程睡眠 Y[sBVz'j5
public static void sleep(int nSecond) 1#tFO
{ S(2_s,J^
try{ /dI8o
Thread.sleep(nSecond); ExKyjWAJ
} Y' FB {
catch(Exception e) nz2`YyR
{ CWdpF>En
e.printStackTrace (); _|jEuif
} Wr+/9
} {q!GTO
zQ~N(Jj?h
//日志 R,8 W7 3
public static void log(String sMsg) :@@aIFRv
{ "UYlC0 S\
System.err.println(sMsg); QtHK`f>4#n
} U%rEW[j
%p;;aZG
:P8X?C63W]
public static void log(int sMsg) h~pQ
{ xp*Wf#BF
System.err.println(sMsg); Bv xLbl}
} H-iCaXT
} +v+Dkyf:V
W"!{f
#;0F-pt
/* Ua.%?V
**TestMethod.java * ,Le--t
*/ |mQC-=6t;Y
package NetFox; 1lYQR`Uh
:z-?L0C=0
K%.t%)A_3
public class TestMethod { 9 lXnNK |]
zI= 9
MX"M2>"pT
public TestMethod() bjBXs;zr@\
{ ///xx/weblogic60b2_win.exe 9K>~9Za
try{ 4(? Z1S
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); LEg ?/!LIT
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G%fXHAs.+
SiteFileFetch fileFetch = new SiteFileFetch(bean); 4axuE]
fileFetch.start(); Tmk'rOg5
} ,(B/R8ZF~
catch(Exception e){e.printStackTrace ();} e$`;z%6y
gb=tc`
siOyp]
} A;TNR
" 1h~P,
=d$m@rc0r
public static void main(String[] args) ;EsfHCi)
{ *QT7\ht3
new TestMethod(); _D{{C
} \0;EHB
} [5PQrf~Mo
点击下载更多相关资料