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)); }Ghh%]
} 9im<J'
for(int i=0;i<nEndPos.length-1;i++) /c4@QbB
{ 5H{dLZ],
nEndPos = nStartPos[i+1]; XX9u%BZ~
} _+0QQ{'N
nEndPos[nEndPos.length-1] = nFileLength; kv8 /UW
} jI%g!
} Q($.s=&l;
Vi:<W0:
)a;ou>u
//启动子线程 KD(}-zUs
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; sM _m
for(int i=0;i<nStartPos.length;i++) CS\ E]f
{ #q-7#pp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), A}h`%b
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), h ycdk1SN
nStartPos,nEndPos,i); :enmMB#%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ? CabVj-r
fileSplitterFetch.start(); OZCbMeB{+J
} IPTEOA<M[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q\I2lZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 9FKowF_8
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", PKK18E}{%^
nEndPos = " + nFileLength); jn:9Cr,o;g
// fileSplitterFetch[nPos.length-1].start(); qiyX{J7Z
OtsW>L@ O(
"'9[c"Iz
//等待子线程结束 dU<qFxW
//int count = 0; i|/EA7
//是否结束while循环 Z{p)rscX
boolean breakWhile = false; vi8)U]6
F?jFFwim
QVq+';cG
while(!bStop) /t$J<bU
{ }z|@X KA#
write_nPos(); 49Y_ze6L}
Utility.sleep(500); 0DQ\akh
breakWhile = true; PSR21;
B{dR/q3;@
fEgwQ-]
for(int i=0;i<nStartPos.length;i++) c:OFBVZ
{ cZFG~n/
if(!fileSplitterFetch.bDownOver) 6$*\%
{ =VFPZ
breakWhile = false; O&vE 5%x
break; gd=gc<zYP
} '^#=,+ A
} V!XT=Ou?6
if(breakWhile) fa:V8xa
break; qHtonJc
x<lY&KQ0
))xyaYIZkk
//count++; lij>u
//if(count>4) 6|HxBC#4
// siteStop(); 5p]Cwj<u
} W_\~CntyZ
M7x*LiKc2
N#!**Q 0
System.err.println("文件下载结束！"); ZaKT~f%%z
} /ZpwJc`e
catch(Exception e){e.printStackTrace ();} ) Z^b)KAk
} 8gK <xp
dF#`_!4pbf
BJ,D1E
//获得文件长度 grWmF3c#
public long getFileSize() w /l\p3n
{ xJemc3]2
int nFileLength = -1; O3];1ud
try{ >dU.ic?19
URL url = new URL(siteInfoBean.getSSiteURL()); z<h?WsL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O S%
httpConnection.setRequestProperty("User-Agent","NetFox"); {!]7=K)W9
R8(Bt73
J 6%CF2
int responseCode=httpConnection.getResponseCode(); Dmq_jt
if(responseCode>=400) !YZ$WiPl
{ WNo",Vc
processErrorCode(responseCode); 6{8dv9tK
return -2; //-2 represent access is error %X^K5Io
} .r4M]1Of
5k]xi)%
QH]G>+LI5
String sHeader; wSGW_{;-
W, YYL(L
%'`L+y
for(int i=1;;i++) A."]6R<
{ YZllfw$9
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); K H&o`U(}
//Utility.log(in.readLine()); R'e>YDC
sHeader=httpConnection.getHeaderFieldKey(i); "gQA|NHwV
if(sHeader!=null) +`_Km5=
{ 8F(Vd99I
if(sHeader.equals("Content-Length")) >M-ZjT>
{ T:?01?m
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); FM=-^l,
break; }(-2a*Z;Y
} |(Q !$
} A!bH0=<I
else &E+2
break; ?K>=>bS^h
} 'v?"TZ
} IJzPWs5W:
catch(IOException e){e.printStackTrace ();} 1O@y >cV
catch(Exception e){e.printStackTrace ();} ;:l>Kac
}g]O_fN7~
wB0Ke
Utility.log(nFileLength); >/eV4ma"
q?TI(J+/
K2gg"#ft?
return nFileLength; 4Y!_tZ>
} 66jL2XU<
HgfeSH
"(cMCBVYdA
//保存下载信息（文件指针位置） E3`&W8
private void write_nPos() z($h7TZ$
{ )(`HEl>-9c
try{ Pko2fJt1
output = new DataOutputStream(new FileOutputStream(tmpFile)); J*}Qnl+
output.writeInt(nStartPos.length); azT@S=,
for(int i=0;i<nStartPos.length;i++) Q/u1$&1
{ Bq 9Eu1
// output.writeLong(nPos); m:4Ec>?e
output.writeLong(fileSplitterFetch.nStartPos); E6njmdu
output.writeLong(fileSplitterFetch.nEndPos); $Il:Yw_
} ek9Y9eJ"
output.close(); uL1$yf'
} ![}q9aeT
catch(IOException e){e.printStackTrace ();} }_GI%+t
catch(Exception e){e.printStackTrace ();} < X&{6xu
} } 0^wJs
Z<M?_<3
jJU9~5i?
//读取保存的下载信息（文件指针位置） l$mfsm|{:
private void read_nPos() SIr^\iiOB
{ ^Ox|q_E w}
try{ +\@}IKWl-?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); w]Byl3}Gt
int nCount = input.readInt(); U)B^R
nStartPos = new long[nCount]; a-(OAzQ_
nEndPos = new long[nCount]; E>2~cC*
for(int i=0;i<nStartPos.length;i++) hnD=DLW $
{ cZd{K[fuK
nStartPos = input.readLong(); /ltGSl
nEndPos = input.readLong(); Gj9WUv[P
} N sNk
input.close(); v$_YZm{!<
} |bWvQdN
catch(IOException e){e.printStackTrace ();} `zmjiC
catch(Exception e){e.printStackTrace ();} RV{'[8gM
} -Uu65m~:{k
!GL kAV
fH6mv0
private void processErrorCode(int nErrorCode) WY3D.z-</
{ yWkg4
System.err.println("Error Code : " + nErrorCode); mO|YX/>
} lf?dTPrD
OqNtTk+
//W7$DYEG
//停止文件下载 1GA$nFBVC
public void siteStop() 8n`O{8:fi
{ Bk)*Z/1<x
bStop = true; [<H'JsJl
for(int i=0;i<nStartPos.length;i++) |^!
fileSplitterFetch.splitterStop(); y)%CNH)*x
AFN"#M
<1xs ya[e
} uhJnDo
} 5q Y+^jO]o
//负责部分文件的抓取 ^_C]?D?
**FileSplitterFetch.java IA&NMf;{
*/ ,y%4QvG7a
package NetFox; :K]&rGi,
N~] 4,~
R3,O;9i
import java.io.*; dnXre*rhz
import java.net.*; wx2EMr
I C?bqC+
$-Wn|w+h<a
public class FileSplitterFetch extends Thread { {~u#.(
m?4L>'
THcK,`lX@
String sURL; //File URL sH_5.+,`
long nStartPos; //File Snippet Start Position Z&w/JP?
long nEndPos; //File Snippet End Position |MEu"pY)
int nThreadID; //Thread's ID g E#43
boolean bDownOver = false; //Downing is over Sh(Ws2b7
boolean bStop = false; //Stop identical n +R3
FileAccessI fileAccessI = null; //File Access interface P g{/tMY
5:r*em
A\IQM^i
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException g$P<`.
{ <!m'xOD
this.sURL = sURL; %40uw3
this.nStartPos = nStart; BZr$x8%ki
this.nEndPos = nEnd; Q(gc(bJV
nThreadID = id; k.MAX8
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MfJ8+3@K
} npD`9ff
&R7N^*He
+&j&es
public void run() [h;&r"1
{ ML9nfB^z!
while(nStartPos < nEndPos && !bStop) 8:QnxrODP
{ F4T}HY>nZ
w4UaWT1J
U|2*.''+Q
try{ %;0l1X
URL url = new URL(sURL); U.mVz,k3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Za4X ;
httpConnection.setRequestProperty("User-Agent","NetFox"); w!8xZu
String sProperty = "bytes="+nStartPos+"-"; FK~FC:K
httpConnection.setRequestProperty("RANGE",sProperty); p#fd+
Utility.log(sProperty); Kx[u9MD
93+p~?
gs?=yNL
InputStream input = httpConnection.getInputStream(); eq<giHJM
//logResponseHead(httpConnection); P}dhpU
vsDR@Y}k
h0v4!`PQ-
byte[] b = new byte[1024]; XC NM
int nRead; ]z{f)`;I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ImnN&[Cu
{ IC[iCrB
nStartPos += fileAccessI.write(b,0,nRead); {y0`p1
//if(nThreadID == 1) s1/:Ts[3i
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t^Hte^#S
} _Vj uQ
Ait3KIJ9
2wKW17wj,
Utility.log("Thread " + nThreadID + " is over!"); =Y;w O8
bDownOver = true; &Fxw19[G
//nPos = fileAccessI.write (b,0,nRead); 'c")]{
} iR`c/
catch(Exception e){e.printStackTrace ();} e.<y-b?
} p"lTZ7c:Y
} $: %U`46%s
vi:IO
Ev'BmDk
//打印回应的头信息 ,cg%t9
public void logResponseHead(HttpURLConnection con) fsr0E=nV
{ dDeImSeV
for(int i=1;;i++) M:*^k
{ ;K+'J0
String header=con.getHeaderFieldKey(i); 4PVkKP'/
if(header!=null) vxmz3ht,Q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OB&lq.r
Utility.log(header+" : "+con.getHeaderField(header)); \4B2%H
else /'S@iq
break; n,.ZLuBEX
} &q?A)R
} liuF;*
EP;TfWc}1
"N|gU;~W
public void splitterStop() $2?10}mrx
{ \@ jYY~
bStop = true; $u`v k|\R
} 4z$}e-
yhBf%m
YH%aPsi
} T9,T'y>BD
oK!W<#
@fML.AT
/* -5_[m@Vr
**FileAccess.java |KM<\v(A{
*//文件访问(定位，写) p?q~.YY
package NetFox; R>05MhA+
import java.io.*; qit D{;
2d`:lk%\
XKTX~:
public class FileAccessI implements Serializable{ 0i4X,oHjG
?'I[[KuG
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 i5QG_^X&
RandomAccessFile oSavedFile; gp/_# QVWC
long nPos; Ki"o0u
$xWebz0
:())%Xu3
public FileAccessI() throws IOException qg(rG5kD@
{ h)vRvfcmY
this("",0); /61P`1y(J
} D{4Ehr "T
xK3 xiR
0."TSe83\
public FileAccessI(String sName,long nPos) throws IOException w,'"2^Cwy
{ Fa!6*K\
oSavedFile = new RandomAccessFile(sName,"rw"); cnrS.s=
this.nPos = nPos; `k>h2(@9S
oSavedFile.seek(nPos); f8m%T%]f
} `(RQh@H
RH=Tu6i
BgzER[g|q{
public synchronized int write(byte[] b,int nStart,int nLen) v@6TC1M,
{ %dyEF8)
int n = -1; @y#QHJ.j
try{ ?Cu1"bl
oSavedFile.write(b,nStart,nLen); Hvm+Tr2@
n = nLen; JpFfO<uO
} :-I~-Yj
catch(IOException e) vWM3JH~a6
{ RuW62QSq
e.printStackTrace (); h7EKb-@
} D9#?l<D
r dc}e"v
Q|^TR__
return n; q $Hg\ {c
} j70]2NgX
ZW]Q|vPh4U
7,\Uk|
} sw(dd01a 7
:[#~,TW
}P5zf$
/* _>G=v!
**SiteInfoBean.java w_gPX0N}3n
*/ !_EaF`oh(
package NetFox; i&r56m<
3E!#?N|v
XYKWOrkQqa
public class SiteInfoBean { X>n\@rTo
1-Fz#v7p
Whf7J'
private String sSiteURL; //Site's URL GS%i<HQ3
private String sFilePath; //Saved File's Path ,@_$acm
private String sFileName; //Saved File's Name L=. 4x=%%
private int nSplitter; //Count of Splited Downloading File ?ah<Qf]
=ZsM[wd
MZ(TST"
public SiteInfoBean() @aG1PG{
{//nSplitter的缺省值为5 g[rxKn\Z
//default value of nSplitter is 5 'wo[iNy[
this("","","",5); b9ON[qOMN
} kp4*|$]
Jl"),;Od
blwdcdh
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) > n~l\ fC
{ e7{n=M
sSiteURL= sURL; =sqhPS<>
sFilePath = sPath; iK*2 Z$`lw
sFileName = sName; v;E7UL .w
this.nSplitter = nSpiltter; 6\MJvg\;
3~e"CKD>
G;n'c7BV
} `ym@U(;N
H!F Cerg
N0@&eX|$i4
public String getSSiteURL() 4T-9F
{ >H@ zP8
return sSiteURL; %!r>]M <
} #?xhfSgr
RLypWjMx$
FuOP+r!H
public void setSSiteURL(String value) KzQ\A!qG
{ _YXk,ME!Q
sSiteURL = value; ?|8QL9Q"|
} dOm#NSJVd
f`5e0;zm
vG(Gs=.U
public String getSFilePath() iOB]72dh
{ }+[H~8)5
return sFilePath; y.AF90Q>)
} ZQT14.$L
m6aq_u{W
+\FTR
public void setSFilePath(String value) 5!ll #/ {`
{ /B$"fxFf
sFilePath = value; D6iHkDTg
} ti:qOSIDTA
7$(>Z^ Em
:X>%6Xj?RV
public String getSFileName() Zho d%n3
{ mPNT*pAO
return sFileName; f>)k<-<yj
} <RmI)g>'_^
%]JSDb=C
u>Z0ug6x
public void setSFileName(String value) `.f<RVk-
{ 3~"G(UP
sFileName = value; fF208A7U I
} .:tAZZ
h+k:G9;sS
tT}*%A
public int getNSplitter() AL/q6PWi
{ \UI7H1XDH
return nSplitter; =T)4Oziks
} }/ 6Q3B
]HP aM
1FU(j*~:
public void setNSplitter(int nCount) 0>Y3>vwSl
{ 7Op6>i
nSplitter = nCount; uBLI!N-G
} nB?$W4
} 7:U^Ki
4,m aA
<4z |"(
/* B$aA=+<S
**Utility.java :E/]Bjq$;
*/ {n8mE,;M
package NetFox; $m`?x5rL8
O/^7TBTn<r
75~>[JM
public class Utility { ffK A
x^kV;^ I
:ND5po#(
public Utility() *TY?*H
{ ANEW^\
T:aYv;#0
c&.>SR')
} V`Z-m-V~1
*.wX9g9\
//线程睡眠 ahNpHTPa
public static void sleep(int nSecond) B1>aR 7dsf
{ &wsxH4
try{ Q=lQy
Thread.sleep(nSecond); q]3bGO;
} ^9zL[R
catch(Exception e) V3WHp'1
{ +]-~UsM
e.printStackTrace (); ^ZX71-
} H: Rd4dl,
} [mKPOg-t
1.YDIB||
//日志 VfOm#Ue0q
public static void log(String sMsg) E(Tvj\9
{ JQQP!]%}
System.err.println(sMsg); ~=~|@K
} Sw<@u+Z;%
ftB-gItV
gT$`a
public static void log(int sMsg) F@Qzh
{ RnV )*
System.err.println(sMsg); E7-il;`cKn
} g$<Sh.4A
} Md_S};!QN6
MG<kvx~2
bcFG$},k
/* e[f}Lxln
**TestMethod.java Y.&nxT95=
*/ >[;+QVr;
package NetFox; @l:\0cO
L5/J
LYb@0O<w
public class TestMethod { 6qQdTp{i
[+EmV>Y
n46H7e(ej\
public TestMethod() H^{Eh
{ ///xx/weblogic60b2_win.exe ?|LR@M!S7
try{ {fe[$KQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); <eP`Lu"
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9frLYJz"
SiteFileFetch fileFetch = new SiteFileFetch(bean); !t/I j~o
fileFetch.start(); f QSP]?
} R{"Kh2q_
catch(Exception e){e.printStackTrace ();} Mz,G;x}
&@CcH_d*
(27bNKr
} v7x%V%K
k^B<t'
D+G?:mR
public static void main(String[] args) $'#hCs
{ OKs1irt5
new TestMethod(); *;7~aM
} ^]}+s(
} *#p}>\Y{
点击下载更多相关资料