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)); M|q~6oM
} #]CFA9z
for(int i=0;i<nEndPos.length-1;i++) $&{ti.l
{ =-NiO@5o
nEndPos = nStartPos[i+1]; O.,3|
} !gF9k8\Yr$
nEndPos[nEndPos.length-1] = nFileLength; :4:N f
} r> k-KdS
} u:&o}[
~e `Bq>
#`(WUn0H?
//启动子线程 ]PWDE"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^Dg<Ki
for(int i=0;i<nStartPos.length;i++) sV/l5]b]
{ O:'?n8rWL
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UDy(dn>J:J
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), W3r?7!~
nStartPos,nEndPos,i); uI~s8{0T6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aZ Xmlq
fileSplitterFetch.start(); ~gE:-
} L[g0&b%%-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *>NX%by)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hA}~es=c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P?LlJ5hn
nEndPos = " + nFileLength); %ft &Q
// fileSplitterFetch[nPos.length-1].start(); iCj2"T4TN
r@U3sO#N
Bj Wr5SJ
//等待子线程结束 (Glr\q]jF\
//int count = 0; =w$tvo/
//是否结束while循环 =-KMb`xT
boolean breakWhile = false; 8j5<6Cv_
/ASaB
E<E3&;qD
while(!bStop) HDVW0QaMu
{ 0v)bA}k
write_nPos(); %zBCq"y
Utility.sleep(500); JhHWu<
breakWhile = true; 7 <9yH:1
z'7[Tie
{2&m`Dbm
for(int i=0;i<nStartPos.length;i++) JIm4vS
{ HOoPrB m
if(!fileSplitterFetch.bDownOver) (#D*Pl
{ OFk8>"|
breakWhile = false; WIr2{+#
break; 'G&{GVbXY
} G7GZDi
} P>i%7:OMZA
if(breakWhile) P 1XK*GZ
break; ritBU:6
m2~&#c\
fu[K".
//count++; 5cJ!"
//if(count>4) $e1=xSQp4
// siteStop(); Cx<0 H
} O`G/=/GZ
=,y |00l
80b;I|-T,
System.err.println("文件下载结束！"); NVKC'==0
} 6%,C_7j
catch(Exception e){e.printStackTrace ();} n">u mM;Eh
} nDS}^Ba
5xCT~y/a
8:=n*
//获得文件长度 B* kcNlW
public long getFileSize() $ _j[2EU
{ h4|i%,f
int nFileLength = -1; NLS"eDm
try{ x5}'7,A
URL url = new URL(siteInfoBean.getSSiteURL()); <BFQ:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M`YWn ;
httpConnection.setRequestProperty("User-Agent","NetFox"); >Fio;cn?
54lu2gD'
XfPFo6
int responseCode=httpConnection.getResponseCode(); 7?j;7.i s(
if(responseCode>=400) d^03"t0O]
{ N`@NiJ(O;
processErrorCode(responseCode); N;Dp~(1 J1
return -2; //-2 represent access is error >F1kR\!
} (jjTK'0[
{7u[1[L1
j#r6b]k(Hv
String sHeader; vo>d!rVCV
`?T#Hl>j
`Z:R Ce^
for(int i=1;;i++) N6K*d` o
{ [x=jH>Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <+MyZM(z>
//Utility.log(in.readLine()); -fhN"B)
sHeader=httpConnection.getHeaderFieldKey(i); L`f^y;Y.
if(sHeader!=null) 5oEV-6
{ o#) {1<0vg
if(sHeader.equals("Content-Length")) }En
{ !+>v[(OzM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); qm/Q65>E
break; Zl 9aDg
} _Zk{!
} NBl+_/2'w
else ,.eWQK~
break; FZjHw_pP
} *eI)Z=8
} [Wd-Zn%
catch(IOException e){e.printStackTrace ();} XO#/Fv!
catch(Exception e){e.printStackTrace ();} ;g{qYj_
\(226^|j
8fA_p}wp
Utility.log(nFileLength); mxor1P#|
!It`+0S b
QaUm1i#
return nFileLength; CYOI.#m2
} 4tL<q_
!.2<| 24
8.F~k~srA
//保存下载信息（文件指针位置） F, U*yj
private void write_nPos() @SCI"H%[
{ J>fQNW!{
try{ mF` B#
output = new DataOutputStream(new FileOutputStream(tmpFile)); UOQEk22
output.writeInt(nStartPos.length); c/c$D;T
for(int i=0;i<nStartPos.length;i++) <: &*
{ 21k5I #U
// output.writeLong(nPos); NM ]bgpP
output.writeLong(fileSplitterFetch.nStartPos); zdXkR]
output.writeLong(fileSplitterFetch.nEndPos); *JggU
} 8DP+W$
output.close(); I*9e]m"
} x.Q&$#
catch(IOException e){e.printStackTrace ();} vJAZ%aW
catch(Exception e){e.printStackTrace ();} <ZU=6Hq
} Gt9&)/#
/cc\fw1+
o7IxJCL=Q
//读取保存的下载信息（文件指针位置） hig2
private void read_nPos() [+O"<Ua
{ .<kqJ|SVi
try{ C9p"?vX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); v<Bynd-
int nCount = input.readInt(); y% :4b@<
nStartPos = new long[nCount]; 2]%h$f+
nEndPos = new long[nCount]; E=){K
for(int i=0;i<nStartPos.length;i++) UH3sH t
{ pp9Zb.D\
nStartPos = input.readLong(); mPq$?gdp
nEndPos = input.readLong(); wAnb Di{W
} v\(2&*
input.close(); d)~Fmi;
} qI^ /"k*5
catch(IOException e){e.printStackTrace ();} <n3!{w3<
catch(Exception e){e.printStackTrace ();} C6rg<tCH
} NcY608C
B"%{i-v>**
@?h/B=56
private void processErrorCode(int nErrorCode) 6uKTGc4
{ &89oO@5
System.err.println("Error Code : " + nErrorCode); 0uBl>A7qhn
} 2NB L}x
i<pk6rO1
)BRKZQN
//停止文件下载 j0@[Br%7
public void siteStop() ca+[0w@S
{ uZ;D!2Q a
bStop = true; zt^48~ry
for(int i=0;i<nStartPos.length;i++) ;sHN/eF
fileSplitterFetch.splitterStop(); eb*#'\~'
=y=cW1TG
}NsUnbxT
} =J1rlnaaEL
} #-h\.#s
//负责部分文件的抓取 CKA;.sh
**FileSplitterFetch.java Rp$}YN
*/ fxgr`nC
package NetFox; mFHH515
4DTzSy:x
G7D2{J{1
import java.io.*; ;E'"Ks[GH
import java.net.*; [Y`,qB<B
9{:O{nl
eI@ q|"U
public class FileSplitterFetch extends Thread { $8a(veXd
*b];|n{
2B,] -Mu)
String sURL; //File URL dx;k`r$w
long nStartPos; //File Snippet Start Position +iI&c s
long nEndPos; //File Snippet End Position D-,L&R!`
int nThreadID; //Thread's ID fryJW=
boolean bDownOver = false; //Downing is over E= `6-H{
boolean bStop = false; //Stop identical 1T:Y0
FileAccessI fileAccessI = null; //File Access interface 6 PxW8pn
@^uH`mc
u :F~K
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException O@YTAT&d#
{ dMrd_1
this.sURL = sURL; 5O`dO9g}$
this.nStartPos = nStart; Hk|0HL
this.nEndPos = nEnd; 7#wn<HDY%
nThreadID = id; *28pRvY:b
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Vx @|O%
} YBnA+l*
'g9"Qv?0{`
[V}S<Xp
public void run() ]D,MiDph
{ 5aa<qtUjH
while(nStartPos < nEndPos && !bStop) !Kv@\4
{ A19;1#$=
Ja ,Cvt
k^OV56
try{ pJ ?~fp
URL url = new URL(sURL); >"Q@bQ:e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t+Op@*#%
httpConnection.setRequestProperty("User-Agent","NetFox"); p6vKoI#T
String sProperty = "bytes="+nStartPos+"-"; /y>>JxAEb
httpConnection.setRequestProperty("RANGE",sProperty); pAk/Qxl3eo
Utility.log(sProperty); [xKd7"d/n
iPrLwheb
a<fUI%_
InputStream input = httpConnection.getInputStream(); 8|$3OVS
//logResponseHead(httpConnection); Ka,^OW}<%q
\o';"Q1H
z,|{fKtY}
byte[] b = new byte[1024]; M'!U<Y -
int nRead; [b$4Shx
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LzCw+@-umw
{ WQHd[2Z#e
nStartPos += fileAccessI.write(b,0,nRead); *OyHHq|>q
//if(nThreadID == 1) QFIL)'K
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h;jIYxj
} "kc/J*u-3
M|] "W
HEGKX]
Utility.log("Thread " + nThreadID + " is over!"); P bQk<"J1
bDownOver = true; PdVfO8-
//nPos = fileAccessI.write (b,0,nRead); GHmv} Z
} v 36%Pj`
catch(Exception e){e.printStackTrace ();} |^9BA-nA
} yZ!T8"mz{
} TFuR@KaBR
BT@r!>Nl
#:d =)Qj0
//打印回应的头信息 r$wxk 4%Rz
public void logResponseHead(HttpURLConnection con) ~gu3g^<0v
{ TB;o~>9U
for(int i=1;;i++) !`7B^RZ
{ x\Y $+A,P
String header=con.getHeaderFieldKey(i); 5xOvY
if(header!=null) VAXT{s&4>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); #h@J=Ki
Utility.log(header+" : "+con.getHeaderField(header)); V"!G2&
else Y{*u&^0{
break; r `eU~7
} c_" ~n|
} kD}Y|*]5-5
#A8@CA^d
P/`I.p;
public void splitterStop() 4GB7A]^E
{ 7L^%x3-|&
bStop = true; Xo*DvD
} TYA~#3G)
03j]d&P%d
~l2aNVv;
} V:G>G'Eh0
CwJDmz\tk
Ks\ NE=;5
/* ,E.' o=Z
**FileAccess.java ] 7 _`]7p
*//文件访问(定位，写) Vn~UB#]'3
package NetFox; \qUKP"dr
import java.io.*; v)_nWu
i{I~mrm/'\
sm$(Y.N
public class FileAccessI implements Serializable{ $fgf Y8
#);[mW{F
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 &[hLzlrg
RandomAccessFile oSavedFile; vp(;W,ba:|
long nPos; #b7$TV
wR{'y)$
wW"z
public FileAccessI() throws IOException V _c@b%
{ W14Vm(`N
this("",0); ( 9]_ HW[
} &5L<i3BX
cv/_r#vN
^V%rag
public FileAccessI(String sName,long nPos) throws IOException "HYQqNj?Z
{ B:Z_9,gj-N
oSavedFile = new RandomAccessFile(sName,"rw"); iX\W;V
this.nPos = nPos; C4}*)a
oSavedFile.seek(nPos); (8ht*b.5K
} (|d34DOJ
{vo +gRYYv
+x1eJug4
public synchronized int write(byte[] b,int nStart,int nLen) Tz9`uW~Mf
{ \(">K
int n = -1; j:w{;(1=W
try{ >><.3
oSavedFile.write(b,nStart,nLen); ]QuM<ms
n = nLen; = P
} TO-$B8*nq
catch(IOException e) TT9z_Q5~
{ {-A^g!jT&
e.printStackTrace (); |+$%kJR=
} 1jX3ey~
s[gKc'
cJgBI(S5
return n; 5E0eyW
} xF8}:z0
}$\M{#C~
Iyo@r%I
} oDcKtB+2
+`uY]Q,O
_sy'.Fo
/* y ?G_y
**SiteInfoBean.java j|tC@0A
*/ YJ:3!B>Zo
package NetFox; _uc\ D R
r 6eb}z!i
Ix|~f1*%
public class SiteInfoBean { dSCzx .c
$F.kK%-*
"G:<7oTa
private String sSiteURL; //Site's URL OTZ_c1"K
private String sFilePath; //Saved File's Path .q][? mW3
private String sFileName; //Saved File's Name U4G}DCU
private int nSplitter; //Count of Splited Downloading File -{ u*qtp
`Bn=?9
z>R#H/h+
public SiteInfoBean() 0hZ1rqq8C
{//nSplitter的缺省值为5 _owjTo}
//default value of nSplitter is 5 A?Wk wf
this("","","",5); eh R{X7J
} \Ey~3&x9f
h3gWOU
bw&myzs
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) t4K~cK
{ _ q(Q
sSiteURL= sURL; !AJ]j|@VBd
sFilePath = sPath; 8j1ekv
sFileName = sName; I^Z8PEc+
this.nSplitter = nSpiltter; @d"wAZzD?
@DC)]C2
iq*A("pU
} fa.0I~
Q)af|GW$
6D;^uM2N
public String getSSiteURL() YDmWN#
{ r.0oxH']
return sSiteURL; =l<iI*J. M
} %]p6Kn/>
6#A:}B<?
wcDjg&:=ml
public void setSSiteURL(String value) +\#Fd
{ DG;y6#|p
sSiteURL = value; N_75-S7Cm
} j[6Raf/(n
P%X-@0)
b]gY~cbI8
public String getSFilePath() )R{UXk3q}
{ dPjhq(8 zU
return sFilePath; 6g>)6ux>aV
} 0=v{RQ;W4
+f4W"t
=7 ,Kf}6
public void setSFilePath(String value) d`Q7"}uZ
{ #l1Qe`
sFilePath = value; I_ "Z:v{
} }fhHXGK.
gdj^df+2F
\)m"3yY
public String getSFileName() A~lIa$U$b
{ 4}KU>9YRA
return sFileName; ;BH>3VK
} '4;6u]d)2
FquFRx
g?qKNY
public void setSFileName(String value) k4KHS<n0
{ & 7QH^
sFileName = value; CBD_a#K{
} <rK=9"$y(t
%hT4qzJj
zREJ#r
public int getNSplitter() p {%t q$}.
{ ACBQ3
return nSplitter; 6*1$8G`$8,
} ipKG!
CdhSp$>
4?]oV%aP)
public void setNSplitter(int nCount) +AQDD4bu
{ tGqCt9;<
nSplitter = nCount; /3^P_\,>f
} jv}=&d
} M$CVQ>op:
6GOcI#C9C
F>Y9o-o2
/* S6 }QFx
**Utility.java )bWrd$X
*/ _C+DBA
package NetFox; oK-!(1A-
8@7AE"
<]#o*_aFP
public class Utility { 0P 5BArJ?
\K`jCsT
F ! )-|n}
public Utility() kr_oUXiX
{ -l.pA(O
tjb/[RQ
{ R*Y=Ie
} 3YTIH2z5
q`loOm=y
//线程睡眠 Hcl"T1N*
public static void sleep(int nSecond) nu 7lh6o=
{ 9.Ap~Ay.
try{ vw rRZ"2
Thread.sleep(nSecond); B82,.?
} tBl#o ^
catch(Exception e) +L6" vkz
{ EX 9Z{xX
e.printStackTrace (); =K6c;
} #uWE2*')
} i/:5jI|
@DCJ}hud
//日志 PdM*5g4
public static void log(String sMsg) )H+h;U
{ 9[f%;WaS
System.err.println(sMsg); +wts 7,3
} ^n71'MW
& >b+loF
4.k`[q8
public static void log(int sMsg) r9;`
{ DrFur(=T
System.err.println(sMsg); u[mY!(>nQ
} '8Qw:fh
} SEU\}Ni{
^+a
CSH`pU
/* ,]U[W
**TestMethod.java 7AeP Gr
*/ /b+;: z
package NetFox; THr8o V5
{0fz9"|U
Q(blW
public class TestMethod { 0k.v0a7%
Xvq^1Y?
n`QO(pZ6+
public TestMethod() 59K}
{ ///xx/weblogic60b2_win.exe :r^klJ(m
try{ pzAoq)gg:
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9[,s4sxH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); !3QRzkJX~
SiteFileFetch fileFetch = new SiteFileFetch(bean); 5Fr;
fileFetch.start(); CX.SYr&!R
} t,1in4sN
catch(Exception e){e.printStackTrace ();} /+N|X
>.n;mk
ennR@pg
} ?Oqzd$-
|""=)-5N
?'Oj=k"c7
public static void main(String[] args) QjqBO+
{ hXPocP
new TestMethod(); #_{0Ndp2
} tw-fAMwU
} ,y{0bq9*2
点击下载更多相关资料