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)); 5` Q#2
} VbZZ=q=Kd
for(int i=0;i<nEndPos.length-1;i++) x&7!m
{ ]@<O!fS
nEndPos = nStartPos[i+1]; Bq\%]2;eo{
} fghJj@ES
nEndPos[nEndPos.length-1] = nFileLength; n0cqM}P@;!
} "d{ |_Cf
} C^uXJ~8
[aIQ/&Y
05w_/l+
//启动子线程 O* 7"Q&
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -()CgtSR
for(int i=0;i<nStartPos.length;i++) "EA%!P:d,
{ d^,u"Z9P
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g4U%(3,>D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zHyM@*Gf(
nStartPos,nEndPos,i); [t>}M6?R:
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4Sw)IU~K(
fileSplitterFetch.start(); .)Du ;
} sqsBGFeG
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2o6%P}C
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); LB-4/G$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yQh":"$k
nEndPos = " + nFileLength); VJm).>E3k
// fileSplitterFetch[nPos.length-1].start(); g#:?Ay-m
':J[KWuV
V+DN<F-
//等待子线程结束 cE[4CCpy
//int count = 0; X62GEqff
//是否结束while循环 }]/"auk
boolean breakWhile = false; T,5]EHea
N5o jXX!l%
P)Sw`^d
while(!bStop) `vUilh ^c
{ ](B+ilr
write_nPos(); >NK*$r8
Utility.sleep(500); kJ{X5&,_
breakWhile = true; EQMn'>
va| 1N/&
Hh,q)(Wo
for(int i=0;i<nStartPos.length;i++) /wKL"M-%
{ \&"gCv#
if(!fileSplitterFetch.bDownOver) U+URj <)
{ fgq#Oi}
breakWhile = false; L`tr7EEr
break; w8c71C
} %r?Y!=0
} 7]62=p2R
if(breakWhile) #T&''a
break; 0)+F}SyyD
gm(`SC?a
3+0$=ef
//count++; R>yoMk/u
//if(count>4) /n&w|b%
// siteStop(); G D$o|l]\
} up#W"`"
GMrjZ
B&VruOP0
System.err.println("文件下载结束！"); Jzo|$W
} (~#{{Ja
catch(Exception e){e.printStackTrace ();} t[Qf|#g
} B!4chxzUZ
( hp 52Vse
gQ6_]~4
//获得文件长度 ]oUvC
public long getFileSize() r".*l?=
{ $TGE
int nFileLength = -1; <Y9%oJn%
try{ A_i=hj2f
URL url = new URL(siteInfoBean.getSSiteURL()); M2l0x @|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iP)`yB5`
httpConnection.setRequestProperty("User-Agent","NetFox"); il|e5TD^
$qV, z
V9mqJRFJ:
int responseCode=httpConnection.getResponseCode(); \C#XKk$OE
if(responseCode>=400) TgoaEufS<
{ ]ri5mnB
processErrorCode(responseCode); )[oegfnn-
return -2; //-2 represent access is error N2#Wyt8MC
} '1'De^%6W
Y23- Im
NO+.n)etGb
String sHeader; AY<(`J{
uB_8P+h7
H`d595<=i;
for(int i=1;;i++) @y]ek/
{ D=Jj!;
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _)XQb1]
//Utility.log(in.readLine()); Tr*3:J }
sHeader=httpConnection.getHeaderFieldKey(i); r$T\@oTL
if(sHeader!=null) g(& huS
{ 6Cfu19Dx
if(sHeader.equals("Content-Length")) Lyo!}T
{ >pdWR1ox
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); `\_>P@qz
break; M#Kke9%2
} 4z%::?
} l1HMH?0|
else jlXzfDT
break; =HapCmrx8
} ZRHK?wg'#
} $lVR6|n
catch(IOException e){e.printStackTrace ();} W T~UEK'
catch(Exception e){e.printStackTrace ();} 79`OB##
g\%;b3"#
PDQEI55
Utility.log(nFileLength); /<C}v~r
ut j7"{'k|
Fj;];1nt
return nFileLength; H{M7_1T
} G5A:C(r
\no6]xN;
RGg=dN
//保存下载信息（文件指针位置） x$hhH=
private void write_nPos() 3u[m? Vw
{ r ]s7a?O
try{ 3EkCM_]
output = new DataOutputStream(new FileOutputStream(tmpFile)); X\4d|VJ?m
output.writeInt(nStartPos.length); fJ<I|ZZ
for(int i=0;i<nStartPos.length;i++) Q3"{v0
{ .bYZkO:oy
// output.writeLong(nPos); &X3G;x2;
output.writeLong(fileSplitterFetch.nStartPos); 2i0 .x
output.writeLong(fileSplitterFetch.nEndPos); <fSWX>pR
} aW=c.Q.
output.close(); `)y<X#[8
} 00SYNG!
catch(IOException e){e.printStackTrace ();} R5Pk>-KF
catch(Exception e){e.printStackTrace ();} WoV"&9y
} Z=ZTSl
\3"jW1Wb
}_mVXjF
//读取保存的下载信息（文件指针位置） _+7+90u
private void read_nPos() 2JdzeJb
{ S@Iza9\|@
try{ A>\5fO
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); eR3v=Q
int nCount = input.readInt(); kI?+\k\V`
nStartPos = new long[nCount]; u*}ltR~/
nEndPos = new long[nCount]; atiyQuT6Wh
for(int i=0;i<nStartPos.length;i++) h*>%ou
{ /O[<"Wcz
nStartPos = input.readLong(); t|PQ4g<
nEndPos = input.readLong(); ~7=eHU.@
} yE&WGpT
input.close(); $-=xG&fSz
} B%7Az!GX
catch(IOException e){e.printStackTrace ();} / f5q9sp8
catch(Exception e){e.printStackTrace ();} }]#&U/z
} |lCS^bA3
=cR"_Z[8X
ej,)<*
private void processErrorCode(int nErrorCode) &2,3R}B/
{ HVdy!J
System.err.println("Error Code : " + nErrorCode); CP'b,}Dd?I
} 'kOkwGf!
~U r
X;bHlA-g
//停止文件下载 LwlO)|E
public void siteStop() ]z#+3DaH
{ 6o0}7T%6
bStop = true; oBO4a^D
for(int i=0;i<nStartPos.length;i++) 9r.h^
fileSplitterFetch.splitterStop(); PZ>(cvX&
**V8a-@
n!dXjInV
} yJK:4af;.
} R 7h^ @
//负责部分文件的抓取 a,|Hn
**FileSplitterFetch.java Iq?n*P$
*/ 9])Id;+91
package NetFox; bey:Qj??
%*zV&H
r.q*S4IS.m
import java.io.*; "4IrW6B$9
import java.net.*; W:maE9E=
3+l8VX&u!
AQ&vq$
public class FileSplitterFetch extends Thread { [g bFs-B2/
1Q_Q-Z
=X1oB,W{
String sURL; //File URL !,+<?o y
long nStartPos; //File Snippet Start Position `w&?SXFO8
long nEndPos; //File Snippet End Position )1f%kp#]
int nThreadID; //Thread's ID ]]o?!NX
boolean bDownOver = false; //Downing is over G|oO
boolean bStop = false; //Stop identical G} f9:G
FileAccessI fileAccessI = null; //File Access interface O3V.4tp
tQ*?L
~GE|,Np
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F EUfskv
{ AGl#f\_^
this.sURL = sURL; +Wl]1 c/
this.nStartPos = nStart; uO>x"D5tZ:
this.nEndPos = nEnd; 7Ll?#eun
nThreadID = id; l 88n*O
fileAccessI = new FileAccessI(sName,nStartPos);//定位 p()q)P
} H_ a##z
~470LgpO1
**$kWbS
public void run() @d5$OpL$%
{ J&Db-
while(nStartPos < nEndPos && !bStop) RBz"1hRo`
{ .i {yW
2TG2<wqvE
OMW]9E
try{ 2$o#b.
URL url = new URL(sURL); XuWX@cK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .]H/u "d
httpConnection.setRequestProperty("User-Agent","NetFox"); %+nM4)h
String sProperty = "bytes="+nStartPos+"-"; x<`^4|<
httpConnection.setRequestProperty("RANGE",sProperty); lVuBo&
Utility.log(sProperty); b<!' WpY-
1`1jSx5}.
a ~YrQI-@
InputStream input = httpConnection.getInputStream(); >k ==7#P
//logResponseHead(httpConnection); cTz@ga;!mI
yEMM@5W)8
=),O;M
byte[] b = new byte[1024]; P*jiz@6
int nRead; YZ]}l%e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @3y >|5Y
{ cuC' o\f
nStartPos += fileAccessI.write(b,0,nRead); KWxTN|>
//if(nThreadID == 1) ?2_h.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); =;GmLi3A
} 9_?<T;]"
Hs$HeAp;
n*ROlCxV
Utility.log("Thread " + nThreadID + " is over!"); HE{UgU:tY
bDownOver = true; E,F^!4 rJ$
//nPos = fileAccessI.write (b,0,nRead); yN)(MmX'1
} 2}7_Y6RS*
catch(Exception e){e.printStackTrace ();} _k :BY
} '4It>50b
} ePZAi"k
'gXD?ARW
]&;In,z
//打印回应的头信息 Yn$:|$
public void logResponseHead(HttpURLConnection con) JB%_&gX)v
{ MLlvsa0
for(int i=1;;i++) VFM!K$_
{ |Eh2#K0x4G
String header=con.getHeaderFieldKey(i); ~Ad2L*5S
if(header!=null) !4`:(G59
//responseHeaders.put(header,httpConnection.getHeaderField(header)); }z#M!~
Utility.log(header+" : "+con.getHeaderField(header)); Q>$lf.)
else 1ni72iz\
break; urE7ZKdI
} H5#]MOAP
} t*; KxQ+'?
am!ssF5s
2D:,(
public void splitterStop() H)h^|A/vO
{ *DvX||`&
bStop = true; g-jg;Ri
} Nmd{C(^o
St(jrZb
$&qLrKJ
} * ]
j'Jb+@W?
ZXL'R|?
/* gG@4MXq.
**FileAccess.java ?w!8;xS8
*//文件访问(定位，写) ~NPhVlT
package NetFox; 6`iYIXnz
import java.io.*; *zN~x(0{E
U}4I29M
0Gc:+c7{
public class FileAccessI implements Serializable{ YM#MfL#
wfe4b
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w N`Njm9!
RandomAccessFile oSavedFile; FfxD=\
long nPos; &SPY'GQ!
pH.&C 5kA
i-;#FT+Xc
public FileAccessI() throws IOException PH&Qw2(Sx
{ TDbSK&w :s
this("",0); @)0
} -9.lFuI
$j(d`@.DN~
hr&&b3W3p
public FileAccessI(String sName,long nPos) throws IOException T)%6"rPL3!
{ livKiX`
oSavedFile = new RandomAccessFile(sName,"rw"); (J.Z+s$:2
this.nPos = nPos; pZK 1G
oSavedFile.seek(nPos); [B`4I
} YlUh|sK7m
!q,7@W3i
j24DL+
public synchronized int write(byte[] b,int nStart,int nLen) LLT6*up$
{ 9_d#F'#F
int n = -1; U,p'<rmS
try{ [0105l5
oSavedFile.write(b,nStart,nLen); ~4Gc~"
n = nLen; jUKMDlH
} '(C+qwdRv
catch(IOException e) AX%}ip[PC
{ ,52Lm=n
e.printStackTrace (); Tn/Zs|
} RM,aG}6M)M
tFc<f7k
]LZ#[xnM7
return n; R) :Xs.
} *k;bkd4x
+6l#hO7h
z/h]Jos
} GDC@s<[k
@[?ZwzY:9
0HU0p!yt&
/* N>YSXh`W`y
**SiteInfoBean.java ?;htK_E\*
*/ 2L;=wP2?{
package NetFox; E9>z.vV
Nu?A>Q
%*!6R:gAp
public class SiteInfoBean { n"aF#HR?0d
gm,AH85
i ]8bj5j{
private String sSiteURL; //Site's URL Vt3*~Beb
private String sFilePath; //Saved File's Path mD.6cV
private String sFileName; //Saved File's Name {]8|\CcY?
private int nSplitter; //Count of Splited Downloading File (y6q}#<
62,dFM7
*xpn-hCp<
public SiteInfoBean() P*?|E@;s`
{//nSplitter的缺省值为5 WA1d8nl
//default value of nSplitter is 5 spm)X-[1
this("","","",5); ,j`48S@
} oy#(]K3`O
QICxSk
T?f{.a)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) P (7Q8i'
{ VpYD/Oj4;
sSiteURL= sURL; Yb`b/BMR
sFilePath = sPath; (0#$%US\
sFileName = sName; !~%DR~^`
this.nSplitter = nSpiltter; 4Eu'_>"a
D&"lu*"tg
q78OP}
} o+x! (
ggrYf*
_eq$C=3Ta
public String getSSiteURL() #BcUE?K*N
{ 41d+z>a]
return sSiteURL; <z2.A/L
} `:~Wu/Ogr
gCPH>8JwS0
9O-~Ws ;
public void setSSiteURL(String value) M&hNkJK*G
{ 'R'hRMD9o
sSiteURL = value; d7G@Z|R3p
} 0fBwy/:
SPdEO3
hp/pm6
public String getSFilePath() pO7OP"q1
{ Z}0xK6
return sFilePath; gsEcvkj*
} LFxk.-{=
+%,oq]<[,
;A@DE@^5w
public void setSFilePath(String value) 1aIGC9xQ`
{ :ChXzZ
sFilePath = value; a}f/<-L
} 7?uDh'utt
{_*G"A 9
XKZsX1=@R
public String getSFileName() ,q#SAZ/N
{ !',%kvJI
return sFileName; b/m.VL
} BQ u8$W
{D",ao
@ewi96
public void setSFileName(String value) X)iI]
{ 1;<Vr<.
sFileName = value; x+za6e_k"
} -hm/lxyU
y7!&
+:ms`Sr>
public int getNSplitter() w.J$(o(/
{ L)\<7
return nSplitter; 'Z.C&6_
} Zqe$S +u
f1'X<VA
C@:X9NU
public void setNSplitter(int nCount) FGP^rTP)e
{ e4Qjx*[G
nSplitter = nCount; PPySOkmS3
} T6\]*mlr
} Pf%I6bVN9
Zazs".
z a_0-G%C2
/* Tq)hAZ
**Utility.java \}.bTca
*/ W$,/hB& z
package NetFox; %>9L}OAm
bfncO[Q,?
`S-l.zSZ4B
public class Utility { 2 yANf
ic!% }S?
4[kyzz x
public Utility() N;-%:nC
{ BxV>s+o&]
u ynudO
zY*~2|q,s
} eXnSH$uI
$,/E"G`
//线程睡眠 N3\RXXY
public static void sleep(int nSecond) 2p;I<C:Eo
{ H? z~V-8
try{ 2BF455e
Thread.sleep(nSecond); O>nMeU
} {j`8XWLZZN
catch(Exception e) L;M@]
{ s1::\&`za
e.printStackTrace (); )i:*r8*~
} k\SqDmv
} UNiK6h_%
:5j+^/
//日志 ZQKo ]Kdr
public static void log(String sMsg) pT~3< ,
{ H}G 9gi
System.err.println(sMsg); :8/ 6dx@Y(
} rX5"p!z
F|m &n&
YCb|eS^u
public static void log(int sMsg) =Gzs+6A8
{ S~fP$L5
System.err.println(sMsg); [tt{wl"E
} ??.aLeF&
} 8`)* ?Q9~
k+"7hf=C|
Gukvd6-g9b
/* Srmr`[i
**TestMethod.java ',]Aj!q
*/ L'KKU4zj
package NetFox; Qt>kythi
ZDp^k{AN9a
D8~\*0->
public class TestMethod { )h0>e9z>Y
1c]{rO=taN
u]O}Ub`
public TestMethod() GKF!GbGR@
{ ///xx/weblogic60b2_win.exe (Ly^+Hjg
try{ n=~!x
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3 i>NKS
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); eE .wnn
SiteFileFetch fileFetch = new SiteFileFetch(bean); <=6F=u3PtU
fileFetch.start(); 1oiSmW\
} I Ij:3HP
catch(Exception e){e.printStackTrace ();} :XAyMK7
yN`&oya
t$VRNZ`dy
} LfW:G5@-
8|\ -(:v
VCnf`wZB"
public static void main(String[] args) Zon7G6s9`
{ <zTz/Hk`
new TestMethod(); =a=:+q g
} nr&|
} wexX|B^u
点击下载更多相关资料