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)); PDssEb7
} %.D@{O
for(int i=0;i<nEndPos.length-1;i++) ve /Q6j{
{ (UTt_ry g
nEndPos = nStartPos[i+1]; TNC,{sM
} XA:v:JFS
nEndPos[nEndPos.length-1] = nFileLength; fXYg %
} 52#@.Qa
} s&$Zgf6Z
QJ s/0iw
P A9 ]L
//启动子线程 b9([)8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; S\jN:o#b
for(int i=0;i<nStartPos.length;i++) scUWI"
{ {N$G|bm]u<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), rm4j8~Ef
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Y&5h_3K;<
nStartPos,nEndPos,i); '&}B"1
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S<LHNZu|^A
fileSplitterFetch.start(); 5X-cDY*|
} `7|v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N|h}'p
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); CtA0W\9w5a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 3u8HF-
nEndPos = " + nFileLength); L+s,,k
// fileSplitterFetch[nPos.length-1].start(); iffRGnN^e
"ND 7,rQ
p_QL{gn
//等待子线程结束 8<uKzb(O:
//int count = 0; xFS`#1
//是否结束while循环 -U=bC
boolean breakWhile = false; mOyBSOad4
?ei7jM",
QSy=JC9
while(!bStop) /cDla5eej
{ O.*,e
write_nPos(); 8<6;X7<-
Utility.sleep(500); F 3}cVO2bY
breakWhile = true; P{)eZINlE
!T|X/BR
TP oP%Yj"
for(int i=0;i<nStartPos.length;i++) 70m}+R(`
{ F,`y_71<
if(!fileSplitterFetch.bDownOver) qgU$0enSs
{ @K]D :MSS
breakWhile = false; r!etj3
break; /W/ =OPe
} >9|/sH@W
} w.Ft-RXA W
if(breakWhile) aC$hg+U$G
break; mg*[,_3q33
z.pP~he
\ey3i((L
//count++; t*^Q`V wQ
//if(count>4) +B%ZB9
// siteStop(); ;e_n7>'#%
} ^'C1VQ%
R b6`k^
0AFjO)
System.err.println("文件下载结束！"); hHdH#-O:4"
} h4S,(*V$!
catch(Exception e){e.printStackTrace ();} qV.*sdS>
} +X0?bVT
Jpws1~
sL XQ)Ce
//获得文件长度 4jj@"*^a
public long getFileSize() xO6)lVd
{ grnlJ=
int nFileLength = -1; do%6P^qA
try{ =g$%.
URL url = new URL(siteInfoBean.getSSiteURL()); 9#.nNv*z3
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6<R!`N 6
httpConnection.setRequestProperty("User-Agent","NetFox"); ]7-*1kL8=~
^6|Q$]}Ok
>ZuWsA0q
int responseCode=httpConnection.getResponseCode(); /WB^h6qg
if(responseCode>=400) n_hV;
{ u-At k-2M
processErrorCode(responseCode); ](@Tbm8
return -2; //-2 represent access is error S=ebht=
} *<zfe.
Sim\+SL{#
zVYX#- nv
String sHeader; sC48o'8(
[L"(flY(E
SI)u@3hl&w
for(int i=1;;i++) J O`S
{ Lt.a@\J'_
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ">*PH}b
//Utility.log(in.readLine()); vz*QzVk1
sHeader=httpConnection.getHeaderFieldKey(i); kc\^xq~
if(sHeader!=null) iu2{%S)w
{ Je[wGF:%:$
if(sHeader.equals("Content-Length")) 4}Y2 B$
{ :e`;["(,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \SS1-UbL
break; E=3<F_3W
} U`D/~KJ{Y
} q<yp6Q3^
else $uF}GP_)
break; >Q#_<IcI
} lzN\~5a}
} lW1Al>dW<
catch(IOException e){e.printStackTrace ();} Mk7,:S
catch(Exception e){e.printStackTrace ();} b'4{l[3~nl
{Tl5,CAz
kFW9@!9
Utility.log(nFileLength); \vXo~_-&
{A2(a7vV
DZ |0CB~
return nFileLength; +dcBh Dq
} >fPa>[_1
9"KEHf!
vX;WxA<
//保存下载信息（文件指针位置） #TM+Vd$
private void write_nPos() Lf{9=;
{ Wqy|Y*$qT
try{ L]3 V)`}
output = new DataOutputStream(new FileOutputStream(tmpFile)); T$)&8"Xya
output.writeInt(nStartPos.length); +Fp8cT=1
for(int i=0;i<nStartPos.length;i++) Fx*iAH\e
{ H[UV]qO,
// output.writeLong(nPos); -uXf?sTV
output.writeLong(fileSplitterFetch.nStartPos); D.9qxM"Z>
output.writeLong(fileSplitterFetch.nEndPos); W~z 2Q so
} +hI:5(_
output.close(); @r^a/]5D
} 9aFu51
catch(IOException e){e.printStackTrace ();} $DeHo"mg7m
catch(Exception e){e.printStackTrace ();} 8e:J{EG~
} 3,=97Si=
\wEHYz
w5w,jD[
//读取保存的下载信息（文件指针位置） *]NG@^y
private void read_nPos() sa$CCQ
{ lk]q\yO_%
try{ eW,{E)x:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (pN:ETB
int nCount = input.readInt(); O%L]*vIr
nStartPos = new long[nCount]; VAX@'iZr
nEndPos = new long[nCount]; bfcQ(m5
for(int i=0;i<nStartPos.length;i++) +sq'\Tbp
{ byoP1F%
nStartPos = input.readLong(); v% 6uU
nEndPos = input.readLong(); ul$k xc=N
} e`9d&"
input.close(); +e}v)N
} 7yM=$"'d
catch(IOException e){e.printStackTrace ();} F_.rLgGY
catch(Exception e){e.printStackTrace ();} CT,PQ
} GdHFgxI
t%Sgw%f
^S:S[0\,
private void processErrorCode(int nErrorCode) P0VXHE1p
{ $`,10uw
System.err.println("Error Code : " + nErrorCode); :}'5'oVG
} yNCd} 4Ym5
[qbZp1s|(
sG{fxha
//停止文件下载 '/8{Mx+
public void siteStop() SO @d\H
{ n@|5PI"bx
bStop = true; @h7)M:l
for(int i=0;i<nStartPos.length;i++) D$@5$./
fileSplitterFetch.splitterStop(); qF'lh
O*0%AjT6
c\A 4-08
} '. 5&Z
} +~xY}
//负责部分文件的抓取 s^f7w
**FileSplitterFetch.java gQ90>P:
*/ >NLG"[\
package NetFox; rlxZ,]ul
wW &q)WOi
hOFC8g
import java.io.*; _y:-_q
import java.net.*; )Fk*'6
by07l5
uCkXzb9_z
public class FileSplitterFetch extends Thread { e}lF#$
AXnRAW
CjR!dh1w_
String sURL; //File URL ^UU@7cSi|G
long nStartPos; //File Snippet Start Position B xAyjA6
long nEndPos; //File Snippet End Position 3.?G,%S5.$
int nThreadID; //Thread's ID `/ <y0H
boolean bDownOver = false; //Downing is over Sc b'
boolean bStop = false; //Stop identical <pA%|]
FileAccessI fileAccessI = null; //File Access interface E8X(AZ 2
1 S<E=7
5@QJ+@j|
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException F*u"LTH
{ Fnqj^5
this.sURL = sURL; z)tULnR8
this.nStartPos = nStart; ;|qbz]t2(
this.nEndPos = nEnd; ~jz!jF~I
nThreadID = id; gXJtk;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v']Tusmg
} Ei>.eXUD5
RE._Ov>
}H#C<:A
public void run() t@X{qm:%Z
{ 8'WoG]E_
while(nStartPos < nEndPos && !bStop) r:{;HM+
{ oYx4+xH/
<C1w?d$9I
edai2O
try{ wjtFZGx&
URL url = new URL(sURL); uNKf!\Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J497 >w[
httpConnection.setRequestProperty("User-Agent","NetFox"); %-?k [DL6
String sProperty = "bytes="+nStartPos+"-"; ^%5;Sc1V
httpConnection.setRequestProperty("RANGE",sProperty); oUl0w~Xn
Utility.log(sProperty); tt&#4Z
`d c&B
g)!d03Qoy
InputStream input = httpConnection.getInputStream(); \jmT#Gt`9
//logResponseHead(httpConnection); 8I8{xt4
z`H|]${X
- +<ai
byte[] b = new byte[1024]; Ly46S
int nRead; >O]u4G!
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) P*|qbY
{ y3XR:d1cg
nStartPos += fileAccessI.write(b,0,nRead); xiv8q/
//if(nThreadID == 1) Vp$<@Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /np05XhEa
} .(^%M 2:6
vRkVPkZ6|
''^2rF^
Utility.log("Thread " + nThreadID + " is over!"); y$Fk0s*>
bDownOver = true; }!uwWBw`
//nPos = fileAccessI.write (b,0,nRead); Gq=tR`.
} !L[$t~z
catch(Exception e){e.printStackTrace ();} ECsb?n7e
} B#]:1:Qn
} we0haK
ke<l@wO
y_``-F&Z
//打印回应的头信息 %)ri:Qq
public void logResponseHead(HttpURLConnection con) eC[G4
{ :]icW^%
for(int i=1;;i++) aH7@:=B
{ 3mQ3mV:
String header=con.getHeaderFieldKey(i); '7<^x>D|
if(header!=null) :jAsm[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :FUxe kz
Utility.log(header+" : "+con.getHeaderField(header)); z? Iu;X
else s .@Szq
break; qXprD.; }
} qP[_!C.
} I)\{?LdHR
o\<JG?P
FM=XoMP q
public void splitterStop() e%km}mA
{ 5KNa-\
bStop = true; FKtG
} ], IQ~
:*M2@
sa}.o ZpQ
} SJ}PV:x
hwQrmVwvP
mGpBj9jr1
/* s"`Oj5
**FileAccess.java xyP0haE
*//文件访问(定位，写) },=ORIB B:
package NetFox; N(e>]ui
import java.io.*; a51}~V1
~Qd|.T
ol1J1Zg
public class FileAccessI implements Serializable{ x*!*2{
ai<K6)
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 e6>[ZC
RandomAccessFile oSavedFile; y1h3Ch>Y
long nPos; DW>O]\I
SmS6B5j\R
as73/J6
public FileAccessI() throws IOException l1.eAs5U
{ \qDY0hIv t
this("",0); Mr*CJgy
} SBaTbY0
nf-6[dg
Y>{%,d#s_
public FileAccessI(String sName,long nPos) throws IOException E#A}2|7,g
{ [s+FX5'K
oSavedFile = new RandomAccessFile(sName,"rw"); :j#zn~7
this.nPos = nPos; *Z+U}QhHD6
oSavedFile.seek(nPos); , {}S<^?]
} |kF"p~s
T2A74>Nw
8.&P4u i
public synchronized int write(byte[] b,int nStart,int nLen) /!_FE+
{ =eR#]d
int n = -1; .zy2_3:
try{ /uPMzl
oSavedFile.write(b,nStart,nLen); #3O$B*gV6
n = nLen; &gP1=P,!
} YkQ=rurE
catch(IOException e) 9 ge'Mo
{ lmIphOUoIw
e.printStackTrace (); u`XZtF<vf
} gk}.LE
1wE`kbC<
[B^V{nUBc
return n; &Z}}9dd
} a *bc#!e
@7t*X-P.;-
4<- E0
} l}FA&c"
+jN)$Y3Ya
Bnz}:te}
/* gF]IAZCi
**SiteInfoBean.java ?IDkDv!na~
*/ DG=_E\"#
package NetFox; KfSbm?
qL$\[(
!95Q4WH-@
public class SiteInfoBean { {)4@rM
+3pfBE|
MnQ 6 !1Z
private String sSiteURL; //Site's URL ]>0$l _V
private String sFilePath; //Saved File's Path >w1jfpQ@t$
private String sFileName; //Saved File's Name ;p"#ZS7
private int nSplitter; //Count of Splited Downloading File <^+&A7Q-_
VoyRB2t
M2A3]wd2a
public SiteInfoBean() oMxpdG3y-
{//nSplitter的缺省值为5 &!*p>Ns)e
//default value of nSplitter is 5 Va/}|&9
this("","","",5); C@MJn)$4
} R_IT${O
wh3Wuh?x
h m(
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BO 3z$c1yU
{ ^C8f(
sSiteURL= sURL; -}5dZ;
sFilePath = sPath; 6f J5Y iQ
sFileName = sName; OSK:Cb.-?F
this.nSplitter = nSpiltter; i;J*9B_U
@ 3b-
cMfnc.P\K
} bR=TGL&
`)H| &!wT
o6X<FE#8
public String getSSiteURL() !/"y
{ PkK#HD
return sSiteURL; 8WwLKZ}
} ab5i7@Ed
i;#AW($+a
E;r~8^9)
public void setSSiteURL(String value) hw&~OJeo
{ tY?evsVgz
sSiteURL = value; Zk #C!]=
} } ejc
Y2>*' nU
k")3R}mX
public String getSFilePath() )1&,khd/u
{ FFc?Av?_
return sFilePath; :5zO!~\
} K st2.Yy
h-@_.&P0e
z"!=A}i
public void setSFilePath(String value) B 3eNvUFZg
{ s`L>mRw`
sFilePath = value; Byns6k
} oX-h7;SD
W0Q;1${
ulXe;2
public String getSFileName() KkZo|\V
{ D]Gt=2\NG9
return sFileName; MLn?t^v-
} G]I^zd&P
":^cb =
d\rs/ee
public void setSFileName(String value) ;hPo5uZQ
{ ,,(BW7(
sFileName = value; -KCQ!0\F
} QsPL^ Ny
4!<[5+.
Oc^bbC
public int getNSplitter() oFS)3.
{ Z9lfd6MU,
return nSplitter; H{*R(S<I
} ;gW?Fnry;
nB ,&m&
YRP$tz+ _
public void setNSplitter(int nCount) j*1O(p+
{ ZSW`/}Dp;
nSplitter = nCount; -cWxS{vO
} n]%yf9,w
} LwIX&\Ub
L3X[; |v}
,9ZN k@q
/* w77"?kJ9X
**Utility.java i9y&<^<W
*/ Y&`nB,'
package NetFox; 31}kNc}n
zI3Bb?4.
X6: c-
public class Utility { jiAN8t*P
3+r8yiY
Uzd\#edxJ
public Utility() MQGR-WV=5
{ v"smmQZik
#k<j`0kiq
,(CIcDJ2U_
} 0~j0x#
T=->~@5
//线程睡眠 C9FQo7
public static void sleep(int nSecond) 8Dy;'BtT
{ k-\RdX)E
try{ g"L$}#iTsl
Thread.sleep(nSecond); fRd^@@,[
} v/WvT!6V`
catch(Exception e) |0/~7l
{ ~!W{C_*N
e.printStackTrace (); _8"%nV
} qU,u(El
} 3.s.&^
m%km@G$
//日志 TwXqk>J
public static void log(String sMsg) )F) (Hg
{ yPza
System.err.println(sMsg); o@KK/f
} .`K<Iug1
|Ptv)D
[.NG~ cpb
public static void log(int sMsg) )R'~{;z }
{ Qtpw0t"
System.err.println(sMsg); DZ Q=Sinry
} Ljjuf=]
} Th)Z?\8zk
/<$\)|r
&*N;yW""f
/* F"Y.'my8
**TestMethod.java Sq,x57-
*/ Q)s[ls
package NetFox; ^p433
Q4,!N(>D
!nkjp[p
public class TestMethod { 3@/\j^U
h+7THMI
kKqb:
public TestMethod() zn'F9rWx>
{ ///xx/weblogic60b2_win.exe F"<TV&xf
try{ &{c.JDO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); hf~'EdU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); GF-\WD
SiteFileFetch fileFetch = new SiteFileFetch(bean); P[E5e+A)
fileFetch.start(); aqk0+
} '=2/0-;Jf
catch(Exception e){e.printStackTrace ();} a.yCd/
2=PX1kI
TxD,A0
} 3b2[i,m<L
]%L?b-e
`i,l)X]
public static void main(String[] args) "NgfdLz
{ %cl=n!T
new TestMethod(); j%m9y_rg}
} `'Af`u\R
} LzW8)<N
点击下载更多相关资料