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)); SBw'z(U
} jar?"o
for(int i=0;i<nEndPos.length-1;i++) R/^;,.
{ 0nlh0u8#
nEndPos = nStartPos[i+1]; H@k$sZ.
} #e9XU:9@g
nEndPos[nEndPos.length-1] = nFileLength; 1fF\k#BE-%
} 6b!1j,\Vx
} HI)U6.'
mFIIqkUAL
gJzS,g1]
//启动子线程 z]O>`50Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; b|`
for(int i=0;i<nStartPos.length;i++) fK=vLcH
{ \l 3M\$oS>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZPY84)A_}
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 27H4en; o=
nStartPos,nEndPos,i); #mO.[IuD
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m(WVxVB
fileSplitterFetch.start(); Z,b^f Vw
} %,)Xi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), uRw%`J4H
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $I/RN
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @gJPMgF$F
nEndPos = " + nFileLength); 'wTJX>
// fileSplitterFetch[nPos.length-1].start(); lHPhZ(Z
@(rLn
;nf}O87~
//等待子线程结束 u\UI6/
//int count = 0; 5d82Ms
//是否结束while循环 jY\YSQ
boolean breakWhile = false; u+8?'ZT,
/M_kJe,%
d _koF-7
while(!bStop) TC'^O0aZ_
{ \V.U8asfI
write_nPos(); dtq]_HvTJ
Utility.sleep(500); K+c>Cj}H
breakWhile = true; h$fC/Juit
eD 7Rv<
885 ,3AdA
for(int i=0;i<nStartPos.length;i++) HLM"dmI
{ {{_,YO^w
if(!fileSplitterFetch.bDownOver) :~9F/Jx
{ 90)rOD1B
breakWhile = false; %AuS8'Uf
break; iD9hqiX&
} \t@|-`
} ~# |p=Y
if(breakWhile) KHXnB
break; sFxciCpN
YY<e]CriU
9Uh nr]J.
//count++; :YZMRJL
//if(count>4) v|mZcAz
// siteStop(); x;R9Gc[5
} 1{S" axSL
n-_-;TYH
V|fs"HY
System.err.println("文件下载结束！"); I*K~GXWs#
} >j$CM:w
catch(Exception e){e.printStackTrace ();} BK]q^.7+:
} sxLq'3(
Y,@{1X`0@3
{GiR-q{t
//获得文件长度 QRv2%^L
public long getFileSize() Oj0/[(D-
{ W7"ks(
int nFileLength = -1; vQ}llA h
try{ A3N<;OOk
URL url = new URL(siteInfoBean.getSSiteURL()); YvK8;<k@-?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); aNCIh@m~
httpConnection.setRequestProperty("User-Agent","NetFox"); Dl%NVi+n
cf0Dq~G
5A6d]
int responseCode=httpConnection.getResponseCode(); #\$R^u]!
if(responseCode>=400) m>6,{g)
{ HLU'1As65
processErrorCode(responseCode); 3B|o
return -2; //-2 represent access is error mPxph>o
} K/jC>4/c/
i4N'[ P}
eVDI7W:(Sn
String sHeader; Khxl'qj
T?c:z?j_9
|,Y(YSg.
for(int i=1;;i++) 0>m-J
{ snV,rZ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A|8(3PiP
//Utility.log(in.readLine()); R1FBH:Iu
sHeader=httpConnection.getHeaderFieldKey(i); Llk4=p
if(sHeader!=null) %@5f+5{i!z
{ IXugnvyV
if(sHeader.equals("Content-Length")) &/4W1=>(
{ ?*a:f"vQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); =LS?:Mhm
break; l=ZhHON
} fNc3&=]]
} 2hl'mRW
else v*1UNXU\
break; qde.;Yv9
} Qj?FUxw
} Dg4?,{c9W
catch(IOException e){e.printStackTrace ();} g&H6~ +\
catch(Exception e){e.printStackTrace ();} h\b]>q@
37Z:WJ?
#n7uw
Utility.log(nFileLength); =)(o(bfSKr
b:Dr_|
C$xU!9K[+
return nFileLength; v"Fa_+TVx
} =m=`|Bn
utC]GiR
{mMrD 5
//保存下载信息（文件指针位置） o-B9r+N
private void write_nPos() Q d]5e
{ !q! =VC
try{ n3-u.Fb
output = new DataOutputStream(new FileOutputStream(tmpFile)); `(<XdlOj
output.writeInt(nStartPos.length); |0ahvsrtW
for(int i=0;i<nStartPos.length;i++) !MNUp(:
{ |r!G(an1x4
// output.writeLong(nPos); ? r=cLC
output.writeLong(fileSplitterFetch.nStartPos); nk]jIRy^T
output.writeLong(fileSplitterFetch.nEndPos); NA>h$N
} _) 2fXG!
output.close(); h*{{_3,
} ,2/qQD n/
catch(IOException e){e.printStackTrace ();} s(J,TS#I]
catch(Exception e){e.printStackTrace ();} +Cl(:kfYB
} qdrk.~_
%p)6m2Sb
&aldnJ
//读取保存的下载信息（文件指针位置） (Kd;l&8
private void read_nPos() i2/:' i
{ xWD=",0+
try{ :f?\ mVS+
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0F6^[osqtl
int nCount = input.readInt(); 33DP0OBL^
nStartPos = new long[nCount]; ~mx me6"v
nEndPos = new long[nCount]; I4ZL+a
for(int i=0;i<nStartPos.length;i++) 4:=']C
{ <ZxxlJS)6
nStartPos = input.readLong(); ;(fDR8
nEndPos = input.readLong(); g8 ,V( ^
} }:7'C. ."
input.close(); LX'.up11X5
} aG}ju;
catch(IOException e){e.printStackTrace ();} t&^9o$
catch(Exception e){e.printStackTrace ();} bv$_t)Xh
} Lnbbv *
6uW?xB9
t6BggO"_u
private void processErrorCode(int nErrorCode) :t-a;Q;
{ ;BUJ5
System.err.println("Error Code : " + nErrorCode); j|TcmZGO
} XYhN;U}Z
$As;Tvw.
^AdHP!I
//停止文件下载 G < Z)y#
public void siteStop() ^EWkJW,Yc
{ NypM+y
bStop = true; 2%i_SX[
for(int i=0;i<nStartPos.length;i++) O-y/K2MC*
fileSplitterFetch.splitterStop(); lxx)l(&
e3,TY.,Ay
oa$-o/DhB
} DW&%"$2
} c""*Ng*T
//负责部分文件的抓取 2K4Jkyi
**FileSplitterFetch.java Xptb4]
*/ a|rN %hA4
package NetFox; YyEW}2
g*?)o!_*
VI7f}
import java.io.*; $mOVo'2
import java.net.*; nXPl\|pXt
'8\7(0$c
=&G<^7
public class FileSplitterFetch extends Thread { JoeU J3N
@zo}#.g
e^2e[rp0
String sURL; //File URL Xmr|k:z
long nStartPos; //File Snippet Start Position (?R;u>
long nEndPos; //File Snippet End Position Y|JC+Ee
int nThreadID; //Thread's ID DT *'r;
boolean bDownOver = false; //Downing is over z-};.!L^
boolean bStop = false; //Stop identical 1{D_30sG.
FileAccessI fileAccessI = null; //File Access interface +TzZ
-5;Kyio
W <.h@Rz+
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 0qP&hybL[(
{ eS)2#=
this.sURL = sURL; 7OuzQzhcK
this.nStartPos = nStart; >Y,3EI\
this.nEndPos = nEnd; ?4>uGaU\
nThreadID = id; -+MGs]),
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K5l#dl_T
} >d#oJ?goX
&q~**^;'
L(Ww6oj
public void run() j7r!N^
{ 0zH^yx:ma
while(nStartPos < nEndPos && !bStop) ">pW:apl%
{ 4cZig\mE;
.gY}}Q
X^204K%:
try{ ]MI>"hn
URL url = new URL(sURL); F:$Dz?F0v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (EZ34,k'S
httpConnection.setRequestProperty("User-Agent","NetFox"); 2hB';Dv
String sProperty = "bytes="+nStartPos+"-"; IX/FKSuq
httpConnection.setRequestProperty("RANGE",sProperty); p1}Y|m!
Utility.log(sProperty); e|Ip7`
38Rod]\E
$E=t6WvA
InputStream input = httpConnection.getInputStream(); f1eY2UtWQ
//logResponseHead(httpConnection); %cIF()
7\.Ax
;=rMIi
byte[] b = new byte[1024]; 5<0d2bK$
int nRead; t<`h(RczHI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 'Na \9b(
{ 3,`.$
nStartPos += fileAccessI.write(b,0,nRead); ]J=S\
//if(nThreadID == 1) T9 @^@l$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @(:ah
} |.bp
~&E|;\G
bYzBe\^3q3
Utility.log("Thread " + nThreadID + " is over!"); |=OO$z;q|
bDownOver = true; 9&'I?D&8
//nPos = fileAccessI.write (b,0,nRead); 6~g:"}
} jgiP2k[Xom
catch(Exception e){e.printStackTrace ();} Bx(+uNQ
} kvU0$1
} )G(6=l*
vS~y~uU%6
47Y|1
//打印回应的头信息 K#"@nVWJ.m
public void logResponseHead(HttpURLConnection con) Z_%}pe39B
{ vPG!S{4
for(int i=1;;i++) {$iJYS\
{ v}6YbY Tq
String header=con.getHeaderFieldKey(i); uo1G
if(header!=null) 9Ao0$|@b
//responseHeaders.put(header,httpConnection.getHeaderField(header)); y)3(
Utility.log(header+" : "+con.getHeaderField(header)); h.)2,
else ,5\:\e0H
break; ,2>:h"^
} ~qNpPIrGr
} O$ i6r]j_
5iola}6
{d$S~
public void splitterStop() K{VF_S:
{ !2x"'o
bStop = true; h3;Ij'
} ADX}
#e%.z+7I
Y51XpcXQ
} F~d !Ub$>
C!w@Naj
|D^Q}uT
/* @{_PO{=\C
**FileAccess.java /2u;w!oi.
*//文件访问(定位，写) #f|-l$a)3a
package NetFox; Rn{q/h
import java.io.*; ZP)=2'RY
[[D}vL8d
T GMHo{]
public class FileAccessI implements Serializable{ \Y9=dE}
#py7emu
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 NQfIY`lt'
RandomAccessFile oSavedFile; ?l,i(I
long nPos; $!I$*R&
`Uk,5F5
va8:QHdU
public FileAccessI() throws IOException 1,PFz
{ tBBN62^X
this("",0); NtTLvO6
} Op3 IL/
v,>F0ofJ
%o4d43uZ
public FileAccessI(String sName,long nPos) throws IOException s*k"-5
{ mKpUEJ<a
oSavedFile = new RandomAccessFile(sName,"rw"); >\DXA)nc
this.nPos = nPos; n+GCL+Mo
oSavedFile.seek(nPos); GWE`'V
} `ss]\46>
aDZLabRu
y6*i/3
public synchronized int write(byte[] b,int nStart,int nLen) !hH6!G
{ [RpFC4W
int n = -1; z5'VsK:
try{ l"*>>/U k
oSavedFile.write(b,nStart,nLen); N_0&3PUSM
n = nLen; i0AC.]4e"
} 30H:x@='9
catch(IOException e) ; wHuL\
{ g"Ii'JZ?
e.printStackTrace (); }Xc|Z.6
} e9B,
RTl7vzG
It_yh #s
return n; xBw"RCBz^
} )i!)Tv
:m$%D]WY
gwqK`ww
} kT$4X0}
>8AtT=}w
2!6Kzq
/* O3BU.X1'%
**SiteInfoBean.java _SFD}w3b$
*/ pP/o2
package NetFox; S i>TG
`GDYL7pM(
50R+D0^mh
public class SiteInfoBean { 7I44BC*R~
x<3vA|o
Ol-'2l
private String sSiteURL; //Site's URL r=[}7N
private String sFilePath; //Saved File's Path RCX4;,DHx
private String sFileName; //Saved File's Name 9E#(iP
private int nSplitter; //Count of Splited Downloading File G7=8*@q>:
hWW<]qzA,
U&/S
public SiteInfoBean() O71rLk;
{//nSplitter的缺省值为5 HZ}'W<N
//default value of nSplitter is 5 S8cFD):q
this("","","",5); P4AdfHk
} _k@l-Bj
R 1b`(
j,-7J*A~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .R"L$V$RU.
{ sI'HS+~pU
sSiteURL= sURL; gjWH }(K
sFilePath = sPath; >k#aB.6
sFileName = sName; ;$/G T
this.nSplitter = nSpiltter; u'b_zlW@
bDNd m-
xr2:bu
} mNYz7N
4>HGwk@+8
Lgfr"{C
public String getSSiteURL() U,S286
{ ]rm=F]W/n
return sSiteURL; iau&k`b`
} D-!%L<<
OY#_0p)i
jdp:G
public void setSSiteURL(String value) sJlKN
{ `!8Z"xD
sSiteURL = value; 'W*F[U*&HP
} eH8.O
ZIl<y{
[ub\DLl
public String getSFilePath() 4#9-Z6kOk
{ "LWuN>
return sFilePath; yw<xv-Q=i
} C=cTj7Ub
co80M;4
6hq)yUvo4
public void setSFilePath(String value) 3\G=J
{ }"Cn kg
sFilePath = value; H/&Q,9sU21
} A'8K^,<
"tARJW
Gp+XM
public String getSFileName() { 9$Q|XK
{ z-G (!]:
return sFileName; /f<(K-o]
} '[^2uQc
]Dg0@Y
y~jIAp
public void setSFileName(String value) Gf\_WNrSE+
{ |hM)e*"
sFileName = value; ~S!kn1&O
} R-fjxM*
*Rh .s!@4
)S;ps
public int getNSplitter() n #I}!x>2
{ Q%2Lyt"(
return nSplitter; 5qEdN
} iGk{8Da<
SGd.z6"H
-Wk"o?}q
public void setNSplitter(int nCount) vKC&Qi ;
{ x^2/jUc#B
nSplitter = nCount; CD[=z)<z{
} i%8&g2
} 2kq@*}ys
@|Bp'`j%J
zEfD{I
/* U&$]?3?
**Utility.java |7x^@i9w
*/ 'LLx$y.Ei[
package NetFox; p|V1Gh<
9[E$>o"%
Aq'E:/
public class Utility { Qmx~_
_ D}b
>C&<dO#i
public Utility() rxp9B>~
{ u>6/_^iq
kGV`Q
t>@3RBEK
} =e-aZ0P
gr{Sh`Cm-
//线程睡眠 HCkqh4
public static void sleep(int nSecond) GSnHxs)
{ aEdJri
try{ gD+t'qg$
Thread.sleep(nSecond); T)tHN#6I
} jI<WzvhYG
catch(Exception e) |Umfq:W`y_
{ qgsE7 ]
e.printStackTrace (); Yf)|ws?!
} H6S vU
} QN&^LaB<T
'=G Ce%A
//日志 0+y~RTAVB
public static void log(String sMsg) 7"NJraQ6
{ L8xprHgL
System.err.println(sMsg); AaC1||?R
} KXA)i5z
,W8Iabi^
64rk^Um
public static void log(int sMsg) 8Pr7aT:,
{ UMi`u6#
System.err.println(sMsg); 53*, f
} ~G:2iSi(#
} UQ?OD~7
q;0&idYC
+y4AUU:Q
/* !"x7re
**TestMethod.java v;}`?@G
*/ ?&<o_/`-H5
package NetFox; IgR"euU
^C)TM@+
<CKmMZ{
public class TestMethod { Ar7mH4M
J1Ki2I=
?-::{2O)
public TestMethod() ]v\egfW,W
{ ///xx/weblogic60b2_win.exe /b:t;0G
try{ m_Ac/ctf
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K_+;"G
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); b801OF
SiteFileFetch fileFetch = new SiteFileFetch(bean); }wOpPN[4
fileFetch.start(); fxoi<!|iGY
} d O46~
catch(Exception e){e.printStackTrace ();} MjXE|3&
!MJe+.
Cq*}b4^;
} I`'a'
<k\H`P
u|OzW}xb7j
public static void main(String[] args) it\DZGsg
{ 0+<eRR9-
new TestMethod(); Ph#F<e(9
} ig2+XR#%
} ,c%K)KuPK.
点击下载更多相关资料