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)); z>rl7&[@
} v]UT1d=_T
for(int i=0;i<nEndPos.length-1;i++) |sP;`h}I%
{ \$.8iTr@
nEndPos = nStartPos[i+1]; V2As 5
} fhGI
nEndPos[nEndPos.length-1] = nFileLength; TPjElBh
} {z~n`ow
} } + ]A?'&
cR'l\iv+
or~2r8
//启动子线程 cEI "
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *$K_Tii
for(int i=0;i<nStartPos.length;i++) a_jw4"Sb
{ |\/`YRg>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gEghDO_G
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 00jWs@K
nStartPos,nEndPos,i); Q&j-a;L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z TYHwx
fileSplitterFetch.start(); +ZFw3KEkz
} #m x4pf{
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ='!E;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ST#9auw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E@}N}SR
nEndPos = " + nFileLength); Iw)}YZmn
// fileSplitterFetch[nPos.length-1].start(); M]c"4b;
>6Y@8 )
j)G<PW
//等待子线程结束 lZ5LHUzP
//int count = 0; k }amSsE
//是否结束while循环 6pJFrWe{
boolean breakWhile = false; ~Up5+7k@
%y96]e1
e}f#dR+(
while(!bStop) 7+!FZo{?
{ dC'8orFG+
write_nPos(); `O+}$wP
Utility.sleep(500); =Msr+P9Ai
breakWhile = true; Qy4eDv5
VQ}N&H)`
KgD sqwy
for(int i=0;i<nStartPos.length;i++) 5#275Hyv
{ qLjLfJJ2
if(!fileSplitterFetch.bDownOver) NUO#[7OK+x
{ NL^;C3u
breakWhile = false; |WkWZZ^
break; 1tZ7%0R\g]
} LZ=E
} CMhl*dH
if(breakWhile) 8}M-b6RV
break; v[Mh[CyB
3VZ}5
14~#k%zO(
//count++; $)YalZ
//if(count>4) at|.Q*&a#
// siteStop(); FOyANN'
} ;W 3#q:
UuKW`(?^
iFOa9!_0n
System.err.println("文件下载结束！"); *Uw"`l
} uv|RpIve:
catch(Exception e){e.printStackTrace ();} ul-O3]\'@
} /Moyn"Kj{
9GX'+$R]
>6KwZr BB
//获得文件长度 f8?hEa:js
public long getFileSize() ?vBMx _0
{ *b4W+E
int nFileLength = -1; P<CPA7K
try{ |jI|},I
URL url = new URL(siteInfoBean.getSSiteURL()); swz)gh-*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :@b=;
httpConnection.setRequestProperty("User-Agent","NetFox"); Dnl|B\
}~v&
a9uMgx}
int responseCode=httpConnection.getResponseCode(); %$<v:eMAs
if(responseCode>=400) \4j(el
{ < ZG!w^
processErrorCode(responseCode); >:bXw#w]
return -2; //-2 represent access is error ;uho.)%N`F
} hRQw]
en"\2+{Cg
vkLKzsN' ]
String sHeader; Q5&|1m Pb
sis1Dh9:
{(IHHA>
for(int i=1;;i++) ^v&"{2
{ 2c'<rkA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \Ez&?yb/
//Utility.log(in.readLine()); SN 4JX
sHeader=httpConnection.getHeaderFieldKey(i); 9T\\hM)k
if(sHeader!=null) b5#Jo2C`AJ
{ y5j ;Daq
if(sHeader.equals("Content-Length")) <Zo{D |hW
{ ?@^gpVK{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Elt"tJ
break; 3T /_#=9TV
} RNopx3
} _Qq lOc9
else EeQ2\'t
break; ck$>
} ,ZZ5A;)
} DFbhy
catch(IOException e){e.printStackTrace ();} )m Ii.
catch(Exception e){e.printStackTrace ();} \D-X _.v
g'9~T8i& ^
`NQ;|!
Utility.log(nFileLength); wkY$J\J
w^ X@PpP
I :8s3;
return nFileLength; / <+F/R'=O
} Q$5%9
W!|l_/L'
CropHB/t
//保存下载信息（文件指针位置） BO+to.
private void write_nPos() ?weuq"*a
{ k&:~l@?O
try{ T[-Tqi NT
output = new DataOutputStream(new FileOutputStream(tmpFile)); s~A:*2\
output.writeInt(nStartPos.length); @cQ |`
for(int i=0;i<nStartPos.length;i++) 6%V#_]
{ @P">4xVX{
// output.writeLong(nPos); )"g @"LJ=
output.writeLong(fileSplitterFetch.nStartPos); #dFE}!"#`
output.writeLong(fileSplitterFetch.nEndPos); aqgm
} Hn]6re
output.close(); H{uR+&<
} "2:#bXM-
catch(IOException e){e.printStackTrace ();} q8&^E.K
catch(Exception e){e.printStackTrace ();} E?jb?
} M(:_(4~
AgWG4C=
t'DIKug&
//读取保存的下载信息（文件指针位置） }:\e"Bfv
private void read_nPos() F<O<=Ww
{ =%{E^z>1
try{ SJlL!<i$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =kw6<!R
int nCount = input.readInt(); C9j5Pd5q1L
nStartPos = new long[nCount]; d 1 O+qS
nEndPos = new long[nCount]; :eBp`dmn
for(int i=0;i<nStartPos.length;i++) \wp8kSzC
{ }7i}dyQv}
nStartPos = input.readLong(); k~]\kv=
nEndPos = input.readLong(); w69G6G(
} sh%%U
input.close(); 0C717
} rUmnv%qTS
catch(IOException e){e.printStackTrace ();} ^ lG^.
catch(Exception e){e.printStackTrace ();} ze`qf%
} scZ'/(b-E
$oIGlKc:L
iJk/fvi
private void processErrorCode(int nErrorCode) !6_tdZ
{ *jl_,0g]
System.err.println("Error Code : " + nErrorCode); {/XU[rn
} 7mYBxE/
/?C6oj1
~{D:vj4>
//停止文件下载 2vW@d[<J
public void siteStop() h}%yG{'/M=
{ {'Gu@l
bStop = true; EU()Nnm2
for(int i=0;i<nStartPos.length;i++) y9Q"3LLic`
fileSplitterFetch.splitterStop(); Of{'A
WhL1OG
Q?Uk%t\hwc
} [~ |e:
} v?h8-yed
//负责部分文件的抓取 <$`udP@
**FileSplitterFetch.java =_d-MJy~6
*/ po+1
package NetFox; JmVha!<qk
1;9 %L@
g$S<_$Iey
import java.io.*; ,DbT4Ul c
import java.net.*; l7GLN1#m
}UHoa
:aMp,DfM]P
public class FileSplitterFetch extends Thread { _xXDvBU
w5}2$r
(?zZvW8
String sURL; //File URL 2BIOA#@t
long nStartPos; //File Snippet Start Position JY@x.?N5$
long nEndPos; //File Snippet End Position `!g XA.9Uv
int nThreadID; //Thread's ID %GDs/9
boolean bDownOver = false; //Downing is over mH09* Z
boolean bStop = false; //Stop identical $kk!NAW
FileAccessI fileAccessI = null; //File Access interface W>]=0u4
`'<&<P
#oD*H:%*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^k}jPc6
{ }[I|oV5*+&
this.sURL = sURL; ^<O:`c6_
this.nStartPos = nStart; cc$+"7/J^c
this.nEndPos = nEnd; REwZ41
nThreadID = id; )*3sE1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 VR_bX|
} jR&AQ-H&
gL;tyf1P
r`(U3EgP
public void run() 18U CZ;)>
{ O}_Z"y
while(nStartPos < nEndPos && !bStop) FzGla})
{ nLjo3yvV..
h|Uy!?l
K-*q3oh G
try{ [-Dl,P=
URL url = new URL(sURL); t Sf`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hgi9%>oUB
httpConnection.setRequestProperty("User-Agent","NetFox"); c/E6}OWA
String sProperty = "bytes="+nStartPos+"-"; VR9C< tMSi
httpConnection.setRequestProperty("RANGE",sProperty); ua vv
Utility.log(sProperty); }nJG<rY
h47l;`kD-#
O~AOZ^a:2
InputStream input = httpConnection.getInputStream(); hkL[hD
//logResponseHead(httpConnection); 8TnByKZz
~V4&l3o
y(RK|r
byte[] b = new byte[1024]; Ka\%kB>*`
int nRead; SggS8$a`
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) fX2PteA0qX
{ S?_ ;$Cn
nStartPos += fileAccessI.write(b,0,nRead); K)"cwk-
//if(nThreadID == 1) YEx76
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =1"8ua
} O{9h'JU
T9+ ?A l
+}@HtjM
Utility.log("Thread " + nThreadID + " is over!"); VJeN m3WNb
bDownOver = true; xFY;aK
//nPos = fileAccessI.write (b,0,nRead); v+|N7
} nUvxO `2
catch(Exception e){e.printStackTrace ();} bu#}`/\_
} (U |[C*
} UC34AKm
}9xEA[@;
J$?*qZ(oO
//打印回应的头信息 8vcV-+x
public void logResponseHead(HttpURLConnection con) XK>/i}y
{ YFCP'J"Z
for(int i=1;;i++) +)fl9>Mb
{ !:mo2zA
String header=con.getHeaderFieldKey(i); 0VB~4NNR
if(header!=null) +`x8[A)-
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dSb|hA}@
Utility.log(header+" : "+con.getHeaderField(header)); [$Ld>`3
else }I'g@Pw9[
break; (SLAq$gvd
} ~o+HAc`=v
} y$At$i>u
XY8s\DK
5u\si4BL{
public void splitterStop() Wb"*9q06
{ !#nlWX:~
bStop = true; p_jDnb#
} !ldb_*)h
& ;+u.X
5B?>.4R
} wvm`JOP:A
|Y!#`
Y$ ;C@I
/* ]cnLJ^2
**FileAccess.java EIwTx:{F
*//文件访问(定位，写) V>j6Juh
package NetFox; lV-7bZ
import java.io.*; )dJaF#6j
RvYH(!pQ
rs3Uk.Z^'
public class FileAccessI implements Serializable{ lu(<(t,Lbs
V,($I'&/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 92GO.xAD?
RandomAccessFile oSavedFile; jl=<Q.Mm7
long nPos; 5o5y3ibQ
/GNRu
a'ViyTBo
public FileAccessI() throws IOException F t%f"Z
{ K^k1]!W=
this("",0); h@T}WZv
} 7{:| )
RR><so%
J56+eC(
public FileAccessI(String sName,long nPos) throws IOException B3'qmi<
{ Z^>[{|lIA
oSavedFile = new RandomAccessFile(sName,"rw"); m u(HNj
this.nPos = nPos; %lchz/
oSavedFile.seek(nPos); W 0Q-&4
} o*\kg+8
hq/\'Z&!+P
jpqq>Hbg_
public synchronized int write(byte[] b,int nStart,int nLen) 50(/LV1
{ [SgP1>M
int n = -1; pc5-'; n
try{ S'HM|&
oSavedFile.write(b,nStart,nLen); 0yXUVKq3
n = nLen; -@G|i$!
} Gu<3*@Ng
catch(IOException e) <oPo?r|oM|
{ /g712\?M4
e.printStackTrace (); Pv`yOx&nE
} &~U8S^os
l2=.;7IV
tOwwgf
return n; )__vPPko i
} F$ x@]
&Hc8u,|
GdR>S('
} 9'Y~! vY
FqQm*k_
SZ~Ti|^
/* U n2xZ[4
**SiteInfoBean.java JTpKF_Za<
*/ B @UaaWh
package NetFox; 'rRo2oTN
rOB-2@-
xzy7I6X
public class SiteInfoBean { ,Vt7Kiu
' G-]>
c}Y(Myd
private String sSiteURL; //Site's URL UMo=bs
private String sFilePath; //Saved File's Path &6PZX0M
private String sFileName; //Saved File's Name N6$pOQ
private int nSplitter; //Count of Splited Downloading File IO`.]iG
>f19P+
;Mc\>i/
public SiteInfoBean() 75@){ :
{//nSplitter的缺省值为5 !~m)_Q5?~
//default value of nSplitter is 5 tk<dp7y7
this("","","",5); ]OM|Oo
} 06pLa3oi
s9~W( Wi
J+[&:]=P
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) b'O>&V`
{ Gk8"fs
sSiteURL= sURL; z*l3O~mZ
sFilePath = sPath; /lm;.7_J+
sFileName = sName; 4/S4bk*8
this.nSplitter = nSpiltter; 7h<Q{X<A
6~0S%Hz
Y1H8+a5@
} :+/V
- P1OD)B
II)\rVP5
public String getSSiteURL() PLKp<kg
{ N/TUcG|m\
return sSiteURL; }qG{1Er
} &'N{v@Oi)
d%81}4f:
^u:7U4
public void setSSiteURL(String value) A0cC)bd&
{ X +*@
sSiteURL = value; m-dne/%_
} @ _U]U
MJV)| 2C
IaH8#3+a
public String getSFilePath() 8uM>UpX
{ :f ybH)*
return sFilePath; ,<zGvksk
} )~T)$TS
_jR%o1Y}
dfiA- h
public void setSFilePath(String value) &kHp}\
{ Ji :2P*
sFilePath = value; VD;Ot<%
} V2,54YE
U voX\
GX&BUP\
public String getSFileName() =_\5h=`Yx
{ n%"q>
return sFileName; >:Na^+c
} Y]P';C_eP
wP/&k`HQ#i
'LpJ:Th
public void setSFileName(String value) tlV>
{ KF|+#qCN
sFileName = value; n&D<l '4
} Z%y>q|:
2^bq4c4J
|[CsLn;
public int getNSplitter() xpxUn8.
{ iN"kv
return nSplitter; |o6 h:g
} BDNn~aU#m
P_B#
GRB/N1=
public void setNSplitter(int nCount) `$ZX]6G
{ Y|_#yb
nSplitter = nCount; MGfDxHg]
} @HxEp;*NH"
} 6b~Zv$5^Y-
]{{A/ j\
N#Y%+1
/* h=.|!u
**Utility.java FAfk;<#'n+
*/ x9Y1v1!5Pu
package NetFox; $HF. 02{|
+wXrQV
{(w/_C9
public class Utility { =${]j
h$)(-_c3
ah1d0eP
public Utility() `utv@9 _z
{ k<Z^93 S
q&Y'zyHLP
AqB5B5}
} PUV)w\!&is
"^F#oo%L
//线程睡眠 mcy\nAf5%
public static void sleep(int nSecond) Y (x_bJ
{ 9 [v=`
try{ =dx!R ,Bw
Thread.sleep(nSecond); gELku .
} N:GSfM@g
catch(Exception e) BAG) -
{ XE* @*
e.printStackTrace (); 1 0lvhzU
} k"&loh
} /:3:Ky3
ye:pGa w
//日志 /x,gdZPX
public static void log(String sMsg) e:fp8 k<
{ 91qk0z`N
System.err.println(sMsg); Ef{rY|E
} @wy|l)%
P?p>'avP
'bJ!~ML&
public static void log(int sMsg) /ts=DxCC;
{ 11[[HkX@
System.err.println(sMsg); reR><p
} C,~wmS )@
} 1j0OV9-|
\ZX5dFu0
T]-yTsto
/* eQu%TZ(x-$
**TestMethod.java <f.*=/]W2
*/ gF-<%<RV
package NetFox; o(w!x!["
k4fc5P
.) uUpY%K^
public class TestMethod { B4yU}v
*GleeJWz
74Xk^8
public TestMethod() wI><kdz
{ ///xx/weblogic60b2_win.exe UhN16|x
try{ ,@kD9n5#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 1^XuH('
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mR@|]T
SiteFileFetch fileFetch = new SiteFileFetch(bean); vw5f.8T;w
fileFetch.start(); Z:DEET!c'k
} RO[Ko-m|/N
catch(Exception e){e.printStackTrace ();} J ^gtSn^
HM57b>6
1+6:K._C(m
} '{dduHo
%E#OUo[y/
#<0Yx9Jh.
public static void main(String[] args) ,Tc3koi
{ 5OeTOI()&5
new TestMethod(); )]WWx-Uf'
} s3qWTdM
} nfpkWyIu{
点击下载更多相关资料