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)); A?\h|u<
} s~/57S
for(int i=0;i<nEndPos.length-1;i++) ]m RF[b$
{ Fu#Y7)r
nEndPos = nStartPos[i+1]; +OKA_b"wB
} 1RmBtx\<
nEndPos[nEndPos.length-1] = nFileLength; dPRtN@3
} z=u~]:.1O
} +7`u9j.
l;XUh9RF`A
FU^Y{sbDg
//启动子线程 /Ql6]8.P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; VN?<[#ij
for(int i=0;i<nStartPos.length;i++) $B*qNYpPy.
{ HH+TjX/b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Qb@BV&^y&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), d"z*Nb
nStartPos,nEndPos,i); B6-AIPb
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |WQD=J%~(
fileSplitterFetch.start(); oJhEHx[f
} hcj{%^p
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {E3;r7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); }`#j;H$i
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zf}rfn
nEndPos = " + nFileLength); u|(aS^H=q
// fileSplitterFetch[nPos.length-1].start(); -=@K%\\~5
><MGZ?-N
"pR $cS
//等待子线程结束 <<i=+ed8eP
//int count = 0; >qr=l,Hi
//是否结束while循环 F>p%2II/
boolean breakWhile = false; hU |LFjc
}o~Tw?z-|
)kFme=;
while(!bStop) ]eY Qio!
{ 5L/Yi
write_nPos(); Q,ZkeWQ7%
Utility.sleep(500); (L]T*03#
breakWhile = true; D-;J;m \
)tJL@Qo
77)OW$G
for(int i=0;i<nStartPos.length;i++) 9t,aT!f
{ cKaL K#~
if(!fileSplitterFetch.bDownOver) mm3zQ!2j.
{ =9#i<te
breakWhile = false; N;%j#(v j
break; O<gP)ZW~
} E>o&GYc
} T9aTEsA[U
if(breakWhile) '&rw=.cU
break; "-G.V#zI
[RroHXdk+
h}Fu"zK
//count++; Yk(NZ3O
//if(count>4) z1z=P%WK
// siteStop(); \UVT_=Y
} g`y/_
b#bO=T$e-
89 _&X[X
System.err.println("文件下载结束！"); #MmmwPB_
} J$o[$G_Z
catch(Exception e){e.printStackTrace ();} 1',+&2)oj
} k i~Raa/e
h+\$Z]
Ke'YM{
//获得文件长度 oY| (M_;
public long getFileSize() `K1PGibV
{ U`},)$
int nFileLength = -1; ?)i6:76(
try{ gME:\ud$
URL url = new URL(siteInfoBean.getSSiteURL()); 9 ayH:;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O% j,:t'"
httpConnection.setRequestProperty("User-Agent","NetFox"); So3,Z'z=
Cf8R2(-4
lk5_s@V l
int responseCode=httpConnection.getResponseCode(); 7!]k#|u
if(responseCode>=400) aC $h_
{ F!DrZd>\
processErrorCode(responseCode); *}50q9)/
return -2; //-2 represent access is error iX&Z
} 2b vYF;<r
@pyA;>U
74</6T]^
String sHeader; /0'fcjOaQ
y"{UNM|R
r)*_,Fo|
for(int i=1;;i++) 3@#,i<ge:
{ -0[>}!l=G
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (5CX*)R
//Utility.log(in.readLine()); J{v6DYhi
sHeader=httpConnection.getHeaderFieldKey(i); U/~Zk@3j
if(sHeader!=null) [m@e^6F0U
{ 6M2i?c
if(sHeader.equals("Content-Length")) Xlgz.j7XR
{ .-gm"lB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LQuYCfj|
break; o>!~*b';g,
} 9 ;! uV>-H
} ** "s~
else s`dkEaS
break; zjhR9
} 8I|1Pl
} *8(t y%5F0
catch(IOException e){e.printStackTrace ();} TO8\4p*tE
catch(Exception e){e.printStackTrace ();} P7^TRrMF
}pU!1GsO
`^@g2c+d
Utility.log(nFileLength); 6 I>xd
h_}BmJh_
?7uStqa
return nFileLength; KH CdO
} M 2U@gC|{
IT{.^rP
Z2Y583D
//保存下载信息（文件指针位置） wLg:YM"
private void write_nPos() V%Z[,C u+
{ h3vm<R;
try{ 0L 4]z'5
output = new DataOutputStream(new FileOutputStream(tmpFile)); cUX]tiC0
output.writeInt(nStartPos.length); =&<$I
for(int i=0;i<nStartPos.length;i++) 1Rb<(%
{ 7~k~S>sO
// output.writeLong(nPos); ocuNrkZ
output.writeLong(fileSplitterFetch.nStartPos); -t706(#k
output.writeLong(fileSplitterFetch.nEndPos); )r-|T&Sn
} ~`Gcq"7,!
output.close(); X_Of k
} M@z_Z+q9
catch(IOException e){e.printStackTrace ();} fuwpp
catch(Exception e){e.printStackTrace ();} ag*Hs<gi
} Toa#>Z*+Rb
0DP%44Cv9
=.3P)gY)
//读取保存的下载信息（文件指针位置） _s#/f5<:B
private void read_nPos() -^NAHE$bW
{ 71,0v`Z<
try{ smQpIB;
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); jL[Is2<@
int nCount = input.readInt(); ;Bc<u[G
nStartPos = new long[nCount]; 9h{:!
nEndPos = new long[nCount]; "$wPq@
for(int i=0;i<nStartPos.length;i++) r z>zdj5}
{ Y+5A2Z)f[
nStartPos = input.readLong(); pOe`*2[
nEndPos = input.readLong(); )}g4Rvr
} `cTsS
input.close(); ($ 1<Dj:
} Z[A|SyZp
catch(IOException e){e.printStackTrace ();} M#gGD-
catch(Exception e){e.printStackTrace ();} 5 <>agK]
} gpTF^.(
%2FCpre;
?tM].\
private void processErrorCode(int nErrorCode) DcvmeGl
{ M`,Z#)Af
System.err.println("Error Code : " + nErrorCode); ,,-[P*@
} #p:jKAc3
1Z{p[\k
)@&?i.
//停止文件下载 d?+oT0pCH
public void siteStop() bT6)(lm
{ ff+9(P>*
bStop = true; =2V;B
for(int i=0;i<nStartPos.length;i++) q.K$b
fileSplitterFetch.splitterStop(); ClVpb ew
GeW$lA I
^# g;"K0
} z4%F2Czai&
} W1,L>Az^Ts
//负责部分文件的抓取 |$-d,] V
**FileSplitterFetch.java l+kg4y
*/ NCh(-E
package NetFox; XIW:Nk!S
eX),B
R~?;KJ
import java.io.*; vrEaNT$J-
import java.net.*; oL/^[TXjH
XjM)/-w
X;a{JjN
public class FileSplitterFetch extends Thread { rH_:7#.E
uEO2,1+
2n r UE
String sURL; //File URL GP kCgb(
long nStartPos; //File Snippet Start Position h[)aRo
long nEndPos; //File Snippet End Position Oh85*3
int nThreadID; //Thread's ID ?F), 4Q
boolean bDownOver = false; //Downing is over L5P}%1 _
boolean bStop = false; //Stop identical w0`L)f5v
FileAccessI fileAccessI = null; //File Access interface wk7_(gT`0
h+d;`7Z>
g.sV$.T2K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cg5{o|x
{ uNGxz*e
this.sURL = sURL; ] ,aAzjZ
this.nStartPos = nStart; xWZcSIH!
this.nEndPos = nEnd; 80"=Qu{s
nThreadID = id; Br$PL&e~
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wg~`Md
} .*ovIU8
SX<mj
aC6b})^
public void run() YxqQg
{ eBRP%<=>D
while(nStartPos < nEndPos && !bStop) 2%yJo7f$[
{ ;GEu.PdxB
h*LL(ow5
N~KRwsDH
try{ t'/;Z:
URL url = new URL(sURL); _o"3gfH&sJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A0k>Nb\c3
httpConnection.setRequestProperty("User-Agent","NetFox"); g>-[-z$E3
String sProperty = "bytes="+nStartPos+"-"; .qPfi] ty
httpConnection.setRequestProperty("RANGE",sProperty); 9{#|sABGD
Utility.log(sProperty); 'i-O
n\p\*wb
D}U<7=\3H
InputStream input = httpConnection.getInputStream(); YGmdiY:;1
//logResponseHead(httpConnection); Qg.:w
+B|X k[
;I@L
byte[] b = new byte[1024]; #E@i@'T
int nRead; YfU#kvE'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R51!j>[fqM
{ N9|.D.#MF
nStartPos += fileAccessI.write(b,0,nRead); Oo .Qz
//if(nThreadID == 1) ABDUp:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [1MEA;
} {4q:4i
?7ZlX?D[
Y-{BY5E.
Utility.log("Thread " + nThreadID + " is over!"); zQ+t@;g1
bDownOver = true; .O.R
//nPos = fileAccessI.write (b,0,nRead); q,&T$Tw
} Y--8v#t
catch(Exception e){e.printStackTrace ();} kw}1CXD
} 4^^rOi0
} jch8d(`?d
eV%bJkt.
Y6PA\7Y\
//打印回应的头信息 xJGeIh5
public void logResponseHead(HttpURLConnection con) s@iCfXU
{ *?"{T;4u~O
for(int i=1;;i++) <BA&S _=4
{ "uC*B4`
String header=con.getHeaderFieldKey(i); K7VG\Ec
if(header!=null) Vgk,+l!4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); wKbymmG
Utility.log(header+" : "+con.getHeaderField(header)); gI3rF=
else (32nI?)a
break; 9?c^~77
} 5/ju it
} .)zISa*Xy
2:F
"?,6{\y,
public void splitterStop() (\>'yW{f
{ -Lb^O/
bStop = true; ,4,c-
} ZHasDZ8
+eXfT*=u5
0Wm-`ZA
} S$WM&9U
Zw{tuO7}K
jsQ$.)nO
/* 1iDo$]TEK
**FileAccess.java Af<>O$$6
*//文件访问(定位，写) W10fjMC}^
package NetFox; @NE#P&f
import java.io.*; b\S}?{m5
W2N7
.&xNJdsY
public class FileAccessI implements Serializable{ 8m<<tv.
dhkpkt<G8
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4] 1a^@?
RandomAccessFile oSavedFile; ii9/ UtIQ
long nPos; ,+9r/}K]/
gVkI=J
Fo~v.+^?
public FileAccessI() throws IOException Y1\vt+`O
{ 0&@pX~h:
this("",0); c<e\JJY5?
} $twF93u$
I!D*(>
o hlVc%a
public FileAccessI(String sName,long nPos) throws IOException $(=1A>40
{ ]H2aYi$
oSavedFile = new RandomAccessFile(sName,"rw"); $t}1|q|
this.nPos = nPos; ,[L$
oSavedFile.seek(nPos); 1}*;
} jRAL(r|
0g-ESf``{n
q(Q9FonU
public synchronized int write(byte[] b,int nStart,int nLen) 1bkUT_
{ K67? d
int n = -1; ;i>E@
try{ |lV9?#!
oSavedFile.write(b,nStart,nLen); W|U1AXU7/
n = nLen; edx'p`%d5
} n`xh/vGm#
catch(IOException e) E2D8s=r
{ qw1J{xoHW
e.printStackTrace (); qV,j)b3M
} w-Fk&dC69
GR `ncI$z
2z3A"HrlA
return n; f*Js= hvO
} _9r{W65s
^j}sS!p
{m:Rv&T
} W^Y0>W~
;bE6Y]"Rz
B$EP'5@b
/* \'*`te:{
**SiteInfoBean.java ,c l<74d
*/ [{$0E=&0
package NetFox; 89mre;v`
)n@3@NV
q(^J7M)
public class SiteInfoBean { MGDv4cFE.
/GGu` f
YU(*kC8
private String sSiteURL; //Site's URL o#/iR]3
private String sFilePath; //Saved File's Path D7/Bp4I#o
private String sFileName; //Saved File's Name <t{AY^:r
private int nSplitter; //Count of Splited Downloading File (=V[tI+Ngt
A8GlE
3>v0W@C
public SiteInfoBean() *DzPkaYD>
{//nSplitter的缺省值为5 0EXNq*=EE
//default value of nSplitter is 5 vI}S6-"<
this("","","",5); k]pD3.QJ
} ;jI"|v{vnS
"\?G
y:[]+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) %Oqe7Cx>+
{ uf]$@6)
sSiteURL= sURL; vyGLn
sFilePath = sPath; ,5*xE\9G
sFileName = sName; uiA:(2AQ
this.nSplitter = nSpiltter; ygt)7f5
>]8.xkQq
UROi.976D
} q.{/{9
'fFdqsXr
+Q0-jS#d
public String getSSiteURL() S'p`ECfVMA
{ KBA%
return sSiteURL; @A'1D@f#
} e/jM+%
rd4'y~#S
J5( D7rp#
public void setSSiteURL(String value) Fxx2vTV4ag
{ /+O8A}
sSiteURL = value; 15DK\_;
} Hd`p_?3]
-GVG1#5
HWOs@!cL
public String getSFilePath() z ]N~_9w
{ Q9tE^d+%
return sFilePath; qFbUM;
} )0MshgM
})vr*[
v};qMceJ
public void setSFilePath(String value) X$Vz
{ Go7hDmu
sFilePath = value; 5?0gC&WfN
} ]GKx[F{)
)'`AX\
f<p4Pkv
public String getSFileName() <>Ddxmw
{ `h5eej&s(
return sFileName; L#q9_-(#
} ?QT"sj64w
HTyF<K
~7WXjVZ
public void setSFileName(String value) #ic 2ofI
{ ]Ja8i%LjOG
sFileName = value; e4%*I8 ^e
} e`M]ZGrr
9Ru%E>el-
Ilu`b|%D
public int getNSplitter() ruA+1-<f
{ 13_~)V
return nSplitter; bRz^=
} -7z y
*oX]=u&
pQ(eF0KG
public void setNSplitter(int nCount) Ss! 3{VW
{ 5=h'!|iY
nSplitter = nCount; 1$D`Z/N"A
} ;s.5\YZ"k
} yZ)aKwj%U
zQ %z"tQ
2*wO5v
/* >fA@tUQB
**Utility.java \"`>-v"h
*/ bNpIC/#0K
package NetFox; 'L|GClc6)
'S4EKV]
^~<Rzq!
public class Utility { RzJ}CT
p6y0W`U
&DQ4=/Z
public Utility() ka)LK@p6
{ eGe[sv"k
6#x)W
~73i^3yf
} UtBlP+bE?y
i,Wm{+H-O
//线程睡眠 3s_k>cO=
public static void sleep(int nSecond) Q}?N4kg
{ Xm=^\K3
try{ f,HzrHax
Thread.sleep(nSecond); io r [v
} ?}3PJVy?
catch(Exception e) m{$tO;c/Q
{ @f5@0A\0
e.printStackTrace (); :&0yf;>v
} :{i$2\DH6
} bqQO E4;
^c0$pqZ}r
//日志 y.*=Ww+
public static void log(String sMsg) kuj12
{ KjwY'aYwr:
System.err.println(sMsg); '0_j{ig
} -Mi}yi
Op/79]$
j #I:6yA3
public static void log(int sMsg) <A -(&+
{ ;?L!1wklA
System.err.println(sMsg); M o"JV
} Jm(&G
} hLytKPgt
:ONuWNY N
lO2T/1iMTW
/* [71#@^ye
**TestMethod.java ',H$zA?i
*/ XHZ: mLf
package NetFox; Z'}(t,
Vy% :\p+
S\3AW,c]w
public class TestMethod { Dz8:;$/
b%[nB
WE.$at{*h
public TestMethod() y KYP
{ ///xx/weblogic60b2_win.exe iIGI=EwZ
try{ $\,BpZ }3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); iJZ|[jEDV
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JIP+ !2
SiteFileFetch fileFetch = new SiteFileFetch(bean); lLkmcHu
fileFetch.start(); ||=[kjG~
} zD)IU_GWa
catch(Exception e){e.printStackTrace ();} 2B9i R
ovDJ{3L6O
t8DL9RW'
} &>W (l.
LmXF`Y$
xMNNXPz(
public static void main(String[] args) vcw>v={x
{ +dCDM1{_a
new TestMethod(); xBL$]>
} b'7z DZI]
} 8Q^6ibE
点击下载更多相关资料