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)); 9S%gVNxn
} Mlw9#H6
for(int i=0;i<nEndPos.length-1;i++) <aaDW
{ mRH]'dlD7
nEndPos = nStartPos[i+1]; em[F|
} "O[76}I+.q
nEndPos[nEndPos.length-1] = nFileLength; L"h@`3o|
} h.$__Gs
} U%DF!~n
Bh,)5E^m
IZ0$=aB7
//启动子线程 En9]x"_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; J7ekIQgR
for(int i=0;i<nStartPos.length;i++) SMO%sZ]
{ 2 dD<]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m"(d%N7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {[5L96RH%
nStartPos,nEndPos,i); SP*JleQN
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); fG2&/42J
fileSplitterFetch.start(); (kQ.tsl
} (+LR u1z
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qH Ga
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); rm=~^eB
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :{s%=\k {d
nEndPos = " + nFileLength); tOg 8L2
// fileSplitterFetch[nPos.length-1].start(); n [Xzo}
Ik5jwfz
a\69,%!:
//等待子线程结束 S"^KJUUc
//int count = 0; @B'8SLoP
//是否结束while循环 U`9\P2D`/
boolean breakWhile = false; Gr"7w[|+
< mK
'?G[T28
while(!bStop) ,(0XsBL
{ "YzTMKu
write_nPos(); oT)VOkFq
Utility.sleep(500); ^q&wITGI
breakWhile = true; )fMX!#KP
\U*-w:+@
V2s}<uG
for(int i=0;i<nStartPos.length;i++) gQh Ccv
{ "h^#<bPN
if(!fileSplitterFetch.bDownOver) dA)4(0o8fD
{ 3.<6;?
breakWhile = false; G#n^@kc*,
break; Sd\IGy{a
} i9\\evJs
} 12d}#G<q-
if(breakWhile) ^s@*ISY
break; :uwRuPI
ju^"vw
5Vqmv<F;$Z
//count++; rZ.a>'T4
//if(count>4) dI0bTw|s/
// siteStop(); J7?)$,ij%
} ]v@tZ}
rF'^w56
R'9@A\7#
System.err.println("文件下载结束！"); %V%#y $l
} JQ@`EV9,
catch(Exception e){e.printStackTrace ();} F%.9fUo
} v!#`W
&Ev]x2YC
kh?#={]Z
//获得文件长度 ;V"yMWjc
public long getFileSize() T]nR=uK6LL
{ CS;W)F
int nFileLength = -1; K_&c5(-(_
try{ ]\a\6&R
URL url = new URL(siteInfoBean.getSSiteURL()); \buZ?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <Sprp]n 7
httpConnection.setRequestProperty("User-Agent","NetFox"); h#@4@x{
:%uyy5AZ
64!ame}n+
int responseCode=httpConnection.getResponseCode(); W\>^[c/
if(responseCode>=400) I^M#[xA
{ bL'#
processErrorCode(responseCode); 4VmCW"b7h
return -2; //-2 represent access is error d7gH3 l
} 5S\][;u
g^z5fFLg/8
Tw}?(\ya
String sHeader; D0#T-B\#
@7Rt4}g
vzyNc'
for(int i=1;;i++) FI`nRFq)C
{ (pE\nuA\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); T+K` ^xv_L
//Utility.log(in.readLine()); %;<k(5bhGJ
sHeader=httpConnection.getHeaderFieldKey(i); J\xz^%p
if(sHeader!=null) Th~3mf #
{ -Ap2NpZ"t
if(sHeader.equals("Content-Length")) 1=/doo{^
{ #Z|%0r_~
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 6`DwEs?Y{
break; V`g\ja*Y
} m6_~`)R8
} #}/cM2m
else *h*j%
break; C,|nmlDN
} &h7smZO5j
} _@#uIOcE
catch(IOException e){e.printStackTrace ();} ;/?Z<[B
catch(Exception e){e.printStackTrace ();} >}<29Ii
|t&G&)~:
b:FEp'ZS
Utility.log(nFileLength); ot@|blVC8
`'xQ6Sy
B?$01?9V
return nFileLength; yD3bl%uZ
} ;}n9yci#
u#41osUVW>
<}28=d
//保存下载信息（文件指针位置） K-2o9No?j`
private void write_nPos() Gg=aK~q6
{ KFTf~!|
try{ |t4Gz1"q=8
output = new DataOutputStream(new FileOutputStream(tmpFile)); MtpU~c
output.writeInt(nStartPos.length); 9{)Z5%Kz
for(int i=0;i<nStartPos.length;i++) l~]hGLviJE
{ [Krm .)
// output.writeLong(nPos); t4f (Y,v
output.writeLong(fileSplitterFetch.nStartPos); Vqa5RVnI
output.writeLong(fileSplitterFetch.nEndPos); U{T[*s
} BKE\SWu
output.close(); ~rgf{oGz
} WZ^{zFoZ
catch(IOException e){e.printStackTrace ();} w8 ?Pb$Fe
catch(Exception e){e.printStackTrace ();} mP9cBLz
} C1X}3bB
d98))G~W
r/mA2
//读取保存的下载信息（文件指针位置） b$dJ?%W
private void read_nPos() 5nMkd/
{ |MTpU@`p5
try{ ruZYehu1W
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =7 Jy
int nCount = input.readInt(); pT("2:)x
nStartPos = new long[nCount]; V*6l6-y~Ih
nEndPos = new long[nCount]; v2/yw,
for(int i=0;i<nStartPos.length;i++) gHQPhe#n
{ TqS2!/jp
nStartPos = input.readLong(); /hm84La
nEndPos = input.readLong(); u:_sTfKm&
} [NHg&R H
input.close(); opm?':Qst
} p+orBw3
catch(IOException e){e.printStackTrace ();} 9U#\nXM
catch(Exception e){e.printStackTrace ();} Z{Vxr*9oO
} +dqk6RE
OZ(Dpx(Q
/C*~/}
private void processErrorCode(int nErrorCode) Ho|o,XvLv
{ hMNJ'i}
System.err.println("Error Code : " + nErrorCode); Wyy^gJl
} k0H?9Z4k5
NFB*1_m
6N9 c<JC
//停止文件下载 b->eg 8|
public void siteStop() 1pd 9s8CA
{ lemVP'cn
bStop = true; pTcbq
for(int i=0;i<nStartPos.length;i++) *-?Wcz
fileSplitterFetch.splitterStop(); 3.Ji5~
Oq*n9V
7#~4{rjg
} |w=Ec#)t4
} cwk+#ur
//负责部分文件的抓取 )D:9R)m
**FileSplitterFetch.java 6D/uo$1Y
*/ *,"jF!C&[
package NetFox; By2s']bw
7sXy`+TZ->
i~9?:plS
import java.io.*; }P#Vsqe V
import java.net.*; K@q&HV"'.
qOW#Q:T
bsB},pc
public class FileSplitterFetch extends Thread { _~tm7o+js
fZ[kh{|
y&1%1 #8F
String sURL; //File URL i][f#e4
long nStartPos; //File Snippet Start Position F4GP7]
long nEndPos; //File Snippet End Position gh TcB
int nThreadID; //Thread's ID 8jRs=I
boolean bDownOver = false; //Downing is over /r276Q
boolean bStop = false; //Stop identical XAkK:}h
FileAccessI fileAccessI = null; //File Access interface wAw42{M
8h@q
;xfO16fNk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 3FFaEl
{ 92ZWU2"
this.sURL = sURL; Ffnk1/Zy
this.nStartPos = nStart; Y!Drb-U?;
this.nEndPos = nEnd; y>$1UwQ
nThreadID = id; XcOA)'Py
fileAccessI = new FileAccessI(sName,nStartPos);//定位 '0Lov]L
} nt=x]wEC
Vr 8:nP:
M~als3
public void run() RoX &+~
{ jk )Vb
while(nStartPos < nEndPos && !bStop) 3S5^`Ag#
{ @|BD|{k
uG;?vvg>
PkTfJQP8
try{ 0mTEim
URL url = new URL(sURL); H#35@HF*o
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =ai2z2z
httpConnection.setRequestProperty("User-Agent","NetFox"); Zb."*zL
String sProperty = "bytes="+nStartPos+"-"; U2bzUxK
httpConnection.setRequestProperty("RANGE",sProperty); $ADPV,*gG
Utility.log(sProperty); "qawq0P8Z
(%bE~Q2P*<
8"x9#kyU<3
InputStream input = httpConnection.getInputStream(); (_K_`5d;QI
//logResponseHead(httpConnection); Tp?-*K
X'f)7RbT
\b$<J.3
byte[] b = new byte[1024]; 5X0QxnnV
int nRead; Z ] '>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r?pZ72q
{ 1SUzzlRx
nStartPos += fileAccessI.write(b,0,nRead); HMV)U{
//if(nThreadID == 1) :N2E}hxk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W .U+.hR
} T^]7R4Fg
l xe`u}[
3htq[Ren
Utility.log("Thread " + nThreadID + " is over!"); it)ZP H
bDownOver = true; \]8VwsP
//nPos = fileAccessI.write (b,0,nRead); !{(ls<
} `a >?UUT4
catch(Exception e){e.printStackTrace ();} +%XnMl
} 4d`+CD C
} +"8}R~`!
}Gr&w-v
d`Oe_<
//打印回应的头信息 !MoOKW
public void logResponseHead(HttpURLConnection con) T`\]!>eb
{ L+.H z&*@
for(int i=1;;i++) ul@3 Bt
{ I^G^J M!
String header=con.getHeaderFieldKey(i); h=6xZuA\
if(header!=null) F+ukAT
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q_]~0PoH
Utility.log(header+" : "+con.getHeaderField(header)); Ux}W&K/?'
else |gv{z"
break; Efx=T$%^&
} FaY_0G;y
} \0?$wIH?
3+>OGwfQ
a8Uk[^5
public void splitterStop() J4>;[\%m
{ |@RpWp>2
bStop = true; b9uBdo@o
} vd (?$
[jrqzB
1k[GuG%/K
} 6{=_718l`
vk'rA{x
8eJE>g1J
/* ,q#2:b<E
**FileAccess.java l^W uS|G[
*//文件访问(定位，写) MQ`%``
package NetFox; HCj>,^<h
import java.io.*; mI"D(bx\
` 1+%}}!$u
[b/o$zR
public class FileAccessI implements Serializable{ Yw)Fbt^
-bS)=L
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &RO7{,`
RandomAccessFile oSavedFile; '#D8*OP^
long nPos; I]R9HGJNlJ
6G of.:"f
".P){Dep$4
public FileAccessI() throws IOException ~.oj.[}
{ rF] +,4
this("",0); | -+zofx
} "IFgRaP=
/t5p-
]Blf9h7
public FileAccessI(String sName,long nPos) throws IOException F*` t"7Lm
{ bL`eiol6
oSavedFile = new RandomAccessFile(sName,"rw"); ? ?[g}>
this.nPos = nPos; 1nI^-aQ3
oSavedFile.seek(nPos); 3^wC<ZXcD
} BzN@gQo
|^( M{
,T|x)"uA`
public synchronized int write(byte[] b,int nStart,int nLen) ashar&'
{ x[i`S8D
int n = -1; PeTA$Yl
try{ e2w&&B-
oSavedFile.write(b,nStart,nLen); EzpFOqJG
n = nLen; ->gZ)?Fqy
} VkZ.6kV
catch(IOException e) =Op+v"
{ _<*Hv*Zm
e.printStackTrace (); )`+YCCa6F
} pe.QiMW{8
`A)"%~
h<x4YB5Mj
return n; wCCV2tk
} 41Ve}%
=\3Tv
mLyBm
} i9A~<
[4Q"#[V&9
:O-1rD
/* +L%IG
**SiteInfoBean.java ub K7B |p
*/ rv7{Ow_Y
package NetFox; z|N3G E(.@
rHz||jjU
M 2q"dz
public class SiteInfoBean { %,UPJn
BRv x[u
T .n4TmF
private String sSiteURL; //Site's URL 1^G{tlA-
private String sFilePath; //Saved File's Path ,[!LCXp
private String sFileName; //Saved File's Name DjLL|jF
private int nSplitter; //Count of Splited Downloading File P_Hv%g
ig!7BxM)<h
)rtomp:X
public SiteInfoBean() o:p *_>&
{//nSplitter的缺省值为5 szmmu*F,U:
//default value of nSplitter is 5 GJA`l8`SQ
this("","","",5); cg{AMeW
} Log|%P\
S\#17.=
bC6oqF'#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9`B$V##-L
{ SA"8!soY3
sSiteURL= sURL; J'T=q/
sFilePath = sPath; ;zH HIdQ>-
sFileName = sName; _NZ@4+aW
this.nSplitter = nSpiltter; `{Tk@A_yd
p/GVTf
bPbb\|u0d
} l.+yn91%>
3V<&|
>I"V],d!6
public String getSSiteURL() q_[G1&MC
{ I5ZqBB
return sSiteURL; |> enp>
} >3.X?
tJ0NPI56yP
r 2:2,5_
public void setSSiteURL(String value) /)3Lnn{W
{ [1yq{n=
sSiteURL = value; 0JjUAxNq
} R.9V,R5
j2 %^qL
\cJa;WM>
public String getSFilePath() PkuTg";
{ (5Nv8H8|
return sFilePath; `'S0*kMT
} 9 ;i\g=
Cb;WZ3HR
ti@kKz
public void setSFilePath(String value) /~p+j{0L3W
{ Kg\R+i@#<
sFilePath = value; K }$&:nao
} 3L5r*fa
U9hS<}<Ki
OQ&'Dti
public String getSFileName() RP4Ku9hk
{ ~ 5"JzT
return sFileName; {FO$yw=>
} dt\jGD
G4 _,
?Bi*1V<R
public void setSFileName(String value) z(y*hazK
{ Di.3113t
sFileName = value; "Zv~QwC
} $A_]:qI2
<If35Z)~
nw:-J1kWR
public int getNSplitter() #'baPqdO
{ #KlCZ~s
return nSplitter; YX*x&5]lq
} 8+Llx
c3%@Wj:fo
`{v?6:G:Q
public void setNSplitter(int nCount) fh8j2S9J
{ &EGqgNl
nSplitter = nCount; q'[}9e`Q
} 7r#ymQ
} k44Q):ncY7
5*%#o
"UFs~S|e
/* ENVk{QE!
**Utility.java x3+oAb@o/
*/ I?#85l{>
package NetFox; 9p* gU[
HvwYm.$zE
!%(h2]MQ
public class Utility { Fh|#u:n
SymwAS+
R7jmv n
public Utility() ZzGahtx)Y
{ ym,H@~
iRo.RU8>
;h=*!7:
} k*rZ*sSp
Cs3^9m6;d
//线程睡眠 y;cUl, :v
public static void sleep(int nSecond) _n8GWBi
{ q<W=#Sx
try{ W<ZK,kv
Thread.sleep(nSecond); ^>x|z.
} qVqRf.-\
catch(Exception e) g6t"mkMY L
{ /&#XhrT
e.printStackTrace (); lA(Q@yEW
} /'2O.d0}.
} Wm~` ~P
Dn9w@KO
//日志 ocbB&
public static void log(String sMsg) uP3_FX: e
{ sAn0bX
System.err.println(sMsg); w>fdQ!RdP
} /PBaIoJE
~[o4a'
Qp,DL@mp>8
public static void log(int sMsg) `N//A}9
{ cLa]D[H
System.err.println(sMsg); pL=d% m.W
} mMx;yZ
} !rDdd%Z
w.\w1:d
[S]S^ej*8
/* tY${M^^<J
**TestMethod.java vr^~yEr
*/ {#P`^g
package NetFox; x&Vm!,%:1
AmPMY:1i"
0kQPJWF
public class TestMethod { AE`We$!
X[s8X!#
=h6 sPJ
public TestMethod() SnlyUP~P
{ ///xx/weblogic60b2_win.exe Pz#7h*;cw.
try{ c}*2$1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); up3O|lj4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 0_P}z3(M
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1be %G [*
fileFetch.start(); 1axQ)},o@p
} 3nZ9m
catch(Exception e){e.printStackTrace ();} jCAC `
4(neKr5\#
=p^He!
} unJid8Lo
87%*+n:?*
YIt& >
public static void main(String[] args) jc[_I&Oc_
{ 8[CB>-9
new TestMethod(); |{*}|
} OH^N" L
} <e]Oa$
点击下载更多相关资料