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)); uvj`r5ei
} B]5G"4,
for(int i=0;i<nEndPos.length-1;i++) ".T&nS[z
{ YCEdt>5PA
nEndPos = nStartPos[i+1]; <GRrw
} MLn\b0
nEndPos[nEndPos.length-1] = nFileLength; :I^I=A%Pe(
} SFx|9$hXm
} UBvea(z-#
XKepk? E
P|4qbm4%O,
//启动子线程 khtYn.eaL
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \t\ZyPxn
for(int i=0;i<nStartPos.length;i++) V.Ki$0>
{ %,[p[`NRYR
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H8'_.2vwX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), QAmb_:^"d
nStartPos,nEndPos,i); V50FX}i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e|jmOYWG
fileSplitterFetch.start(); V?"SrXN>
} ZF6?N?t}h8
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BX=YS)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); F~tT5?+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", SN/ e41
nEndPos = " + nFileLength); |]8Hh>
// fileSplitterFetch[nPos.length-1].start(); Y1Qg|U o
9py*gN#
*P}v82C N
//等待子线程结束 UuvI?D
//int count = 0; LU4k/
//是否结束while循环 }hd:avze
boolean breakWhile = false; +Pm yFJH
\5s#9
KZ;Q71
while(!bStop) |VRzIA4M\
{ *Af:^>mh
write_nPos(); }+Ne)B E
Utility.sleep(500); jLu`DKB
breakWhile = true; K}p!W"!o
W4~:3Sk
Ot#O];3
for(int i=0;i<nStartPos.length;i++) iI(7{$y
{ G 0;5I_D/
if(!fileSplitterFetch.bDownOver) dy%#E2f
{ Ysz&/ry
breakWhile = false; ApxGrCu
break; lYq4f|5H}m
} R<jt$--H
} }+4^ZbX+:
if(breakWhile) ee|i
break; 1EvK\
{Ex*8sU%p%
%t:pG}A>:C
//count++; \KJ\>2Y
//if(count>4) 3A(sT}
// siteStop(); }+1Y>W7q
} 8Vb.%f&I
{Bb:S"7NX
vhQIkB8
System.err.println("文件下载结束！"); Rg!Fu
} 39(]UO6^;
catch(Exception e){e.printStackTrace ();} "\9!9U#!
} d!i#@XZ^
vS{zLXg
[j]3='2}G
//获得文件长度 - s,M+Q(<
public long getFileSize() U3f a*D
{ G$B( AWL
int nFileLength = -1; Pgg\(D#X`
try{ ub0uxvz
URL url = new URL(siteInfoBean.getSSiteURL()); 5}uH;E)4
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?4 fXCb]7
httpConnection.setRequestProperty("User-Agent","NetFox"); NlS/PWc6(
,#FK3;U
}bxW@(bs
int responseCode=httpConnection.getResponseCode(); l"#}g%E
if(responseCode>=400) mu?6Phj
{ &(]@L\A
processErrorCode(responseCode); dMnJ)R
return -2; //-2 represent access is error Z`=[hu
} D/ SM/
$\ 0d9^)&
t'@qb~sf
String sHeader; +v`?j+6z
F(w
nK"XyZ&
for(int i=1;;i++) u&!QP4$"z
{ 2$MIA?A"Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); vIi#M0@N
//Utility.log(in.readLine()); 5ZRO{rf
sHeader=httpConnection.getHeaderFieldKey(i); MifPZQ
if(sHeader!=null) I-QaR
{ _ZnVQ,zY
if(sHeader.equals("Content-Length")) x!A.**
{ %6vf~oG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wm$1LZ8o-`
break; 8$H_:*A?
} d3$&I==;:
} YB^[HE\#y
else gdu8O!9)
break; %)Pn<! L
} [=63xPxs.
} {q[l4_
catch(IOException e){e.printStackTrace ();} `Eijy3>h
catch(Exception e){e.printStackTrace ();} Ez*9*]O*+
/WlpRf%
yH'vhtop
Utility.log(nFileLength); u7oHqo`
{p{TG5rwX
G8y:f%I!b
return nFileLength; QeK@++EVc
} 1q])"l"<
<F=U(WWn9
3=reN6Q
//保存下载信息（文件指针位置） thYG1Cs
private void write_nPos() dQ5_=(9
{ H>x(c|ZBp
try{ p@H3NX
output = new DataOutputStream(new FileOutputStream(tmpFile)); H WOl79-
output.writeInt(nStartPos.length); !f\q0Gnl
for(int i=0;i<nStartPos.length;i++) PfaBzi9?f
{ J;K-Pv+
// output.writeLong(nPos); Fo=hL
output.writeLong(fileSplitterFetch.nStartPos); |6%B2I&c
output.writeLong(fileSplitterFetch.nEndPos); 'Y ZYRFWXM
} FY^[?lj
output.close(); WW'8&:x
} h@5mVTb}i
catch(IOException e){e.printStackTrace ();} 5ayM}u%\~
catch(Exception e){e.printStackTrace ();} ^r u1QDT
} fgs){Ng`
8| 6:
yA8e"$
//读取保存的下载信息（文件指针位置） rNgFsFQ>.
private void read_nPos() s<i& q {r
{ BM(8+Wj
try{ ]}3AP!:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $c!cO" U
int nCount = input.readInt(); %6\e_y%
nStartPos = new long[nCount]; 9aED6
nEndPos = new long[nCount]; :|s!_G<
for(int i=0;i<nStartPos.length;i++) %>dCAj"
{ u7_IO
nStartPos = input.readLong(); U;Iqz1S
nEndPos = input.readLong(); qP"+SVqC
} %nTgrgS(=
input.close(); _B@=fY(g!
} tSr.0'CE
catch(IOException e){e.printStackTrace ();} /'V(F* g
catch(Exception e){e.printStackTrace ();} ,cbCt
} HC4vet
"k)}qI{
Osb#<9{}
private void processErrorCode(int nErrorCode) h&$7^P
{ td:GZ %
System.err.println("Error Code : " + nErrorCode); kEH(\3,l
} l\PDou@5
j4ARGkK5B
MeXzWLH
//停止文件下载 bbDl?m&bq
public void siteStop() 8i H'cX
{ ax]Pa*C}
bStop = true; r#ISIgJXG
for(int i=0;i<nStartPos.length;i++) rOt`5_2f
fileSplitterFetch.splitterStop(); 39xAh*}G]
Y#>'.$(Az
#J1vN]g
} wABaNB=9;
} hL1q9%
//负责部分文件的抓取 *hhPCYOm
**FileSplitterFetch.java LL|uMe"Jb
*/ DrfOz#a0Uu
package NetFox; w4m-DR5
AY{-Hf&
9~bl
import java.io.*; E8[{U8)[;5
import java.net.*; K%Dksx7ow
9n#Q1Xq
G~SgI>Q
public class FileSplitterFetch extends Thread { [^rT: %Z
[0M2`x4`
4fK(<2i
String sURL; //File URL [D8u.8q
long nStartPos; //File Snippet Start Position Q}pnb3J>T
long nEndPos; //File Snippet End Position ' }G!D
int nThreadID; //Thread's ID ^hG Y,\K9
boolean bDownOver = false; //Downing is over _0~WT
boolean bStop = false; //Stop identical ]}KoW?M
FileAccessI fileAccessI = null; //File Access interface <r6e23
av-l_iE
{[r}&^K15
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zG\g{cB
{ 2~:jg1
this.sURL = sURL; ^Z?X\t
this.nStartPos = nStart; v9<7=D&x
this.nEndPos = nEnd; dQ&S&SW
nThreadID = id; f L @rv
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K+9oV[DMs
} .AEOf0t
ZG=B'4W
+~gqPk
public void run() _R&}CP
{ !ke_?+8sY
while(nStartPos < nEndPos && !bStop) l>l)m-;O
{ aNZJs<3;'D
3kAmRU
?^F*M#%?
try{ cY%[UK$l
URL url = new URL(sURL); c\X0*GX
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'dE G\?v9
httpConnection.setRequestProperty("User-Agent","NetFox"); q+A^JjzT
String sProperty = "bytes="+nStartPos+"-"; 'ZyHp=RN)
httpConnection.setRequestProperty("RANGE",sProperty); q4].C|7
Utility.log(sProperty); RYU(z;+0p
,XD'f
@,Je*5$o"
InputStream input = httpConnection.getInputStream(); #41fRmzC
//logResponseHead(httpConnection); HPc7Vo(
deD%E-Ja
KfC8~{O-
byte[] b = new byte[1024]; xM ]IU <
int nRead; 4vri=P 2%
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q3+G
{ 2k\i/i/Y
nStartPos += fileAccessI.write(b,0,nRead); :K%{?y
//if(nThreadID == 1) 9fk@C/$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #[.vfG
} 'qGKS:8
w]Q0}Z
czMu<@c [
Utility.log("Thread " + nThreadID + " is over!"); $"P9I-\m
bDownOver = true; x/nlIoT
//nPos = fileAccessI.write (b,0,nRead); f1cQ*#2~
} U) tqo_
catch(Exception e){e.printStackTrace ();} g+5{&YD
} 4@,d{qp~
} Y{].%xM5
{`Ekv/XWa
yY,O=yOjq
//打印回应的头信息 pdcP;.
public void logResponseHead(HttpURLConnection con) H*#L~!]
{ @"M%ZnFu
for(int i=1;;i++) :HSqa9>wa
{ ~vD7BO`
String header=con.getHeaderFieldKey(i); sE*A,z?
if(header!=null) ENlqoj1
//responseHeaders.put(header,httpConnection.getHeaderField(header)); PJC[#>}
Utility.log(header+" : "+con.getHeaderField(header)); !Vtt.j &4
else "NUl7ce.R
break; f/spJ<B).4
} [Z2:3*5r.
} X[L6Av
ISHNeO8
@@L@r6
public void splitterStop() [4)q6N5`f
{ (!h%) _?.l
bStop = true; &!I^m
} xkv2#"*v
wJ_E\vP
)9~1XiS,
} SHw%u~[hu
sb 3l4(8g
fo63H'7
/* :e-&,K
**FileAccess.java nSH A,c
*//文件访问(定位，写) [al,UO
package NetFox; pfj%AP:
import java.io.*; d*%-r2K
yZf+*j/a7
9Y:JA]U&8
public class FileAccessI implements Serializable{ ]h0Fv-[A
:Jp$_T&E
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 z7+y{-{Z
RandomAccessFile oSavedFile; ([loWr}QR
long nPos; %|(~k*s4
$y!k)"k
28l",j)S
public FileAccessI() throws IOException ],ow@}
{ ,BM6s,\
this("",0); /1X0h
} i2or/(u`
]?P9M<0PM
x)6yWr[ri%
public FileAccessI(String sName,long nPos) throws IOException te?R(&
{ @kR/=EfS
oSavedFile = new RandomAccessFile(sName,"rw"); M[5zn
this.nPos = nPos; kc&>l(
oSavedFile.seek(nPos); RulZh2C
} n7~!klF-
'L#qR)t
|RqCw7
public synchronized int write(byte[] b,int nStart,int nLen) {p-b,J9~a
{ (5@9j
int n = -1; 8+Lig
try{ 5TlPs_o
oSavedFile.write(b,nStart,nLen); '>:mEXK}w
n = nLen; sa\v9
} MRvtuE|g
catch(IOException e) E.v~<[g
{ Qh%(yL!
e.printStackTrace (); }Sa2s&[<
} #pJ^w>YNy
AL/`Pqlk
1nh2()QI[
return n; HjTK/x'_'L
} /kLX f_
n8"S;:Zm
Ba/Z<1)
} H27J kZ&
J-lQPMI,
ARYqX\-e
/* 41%B%K*
**SiteInfoBean.java ^n5[pF}Gw
*/ 2Up1 FFRx
package NetFox; ;$W/le"Xr
+O23@G?x
|xaJv:96%
public class SiteInfoBean { Mf0g)X}1
T:Dp+m!\{
]saf<?fzr
private String sSiteURL; //Site's URL mLM$dk3
private String sFilePath; //Saved File's Path ;czMsHu0X
private String sFileName; //Saved File's Name iqCKVo7:M
private int nSplitter; //Count of Splited Downloading File hx$-d}W{
Qg+0(odd
d)|{iUcW
public SiteInfoBean() IC}?oXs5G
{//nSplitter的缺省值为5 c }>:>^
//default value of nSplitter is 5 N7j
this("","","",5); VHX&#vm*
} c@:L7#8
<:yB4t3H+q
{HeIY2
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 5,!,mor$]
{ b?h9G3J_a
sSiteURL= sURL; WSfla~-'F
sFilePath = sPath; >`DbT:/<
sFileName = sName; ]X+3"
this.nSplitter = nSpiltter; D/hQ{T
Xr~6_N{J
hd1H
} yvo~'k#c
yEUFK
Ak%M,``(L
public String getSSiteURL() !]Z> T5$
{ K^AX=B
return sSiteURL; XtfO;`
} 9&5\L
06 gE;iT
5,>1rd<B
public void setSSiteURL(String value) 'Omi3LXfDT
{ ^\ &:'$f+8
sSiteURL = value; ]H7_bix
} j.4oYxK!s/
cA ;'~[
W?{:HV
public String getSFilePath() }AG$E}~/
{ ZjY_AbD
return sFilePath; w[PWJ! <
} HbF.doXK
jzc/Olb
H n+1I
public void setSFilePath(String value) ByeyUw
{ YMP:T?vMVh
sFilePath = value; )NZ6!3[@
} %>'2E!%
.EVy?-
9"R]"v3BA
public String getSFileName() O!='U!X@P
{ xbrxh-gV
return sFileName; BR\%aU$u
} +NPk9jn
dC@aQi6{6
(+>~6SE
public void setSFileName(String value) OxX{[|!`
{ rKq/=Avv
sFileName = value; ?_[xpK()
} zLXmjrC
8WV1OIL
Rk^Fasg"
public int getNSplitter() =nOV!!
{ :7p0JGd
return nSplitter; eA&hiAP/
} a&)0_i:r
Pgg6(O9}B^
c"t1E-Nsk
public void setNSplitter(int nCount) 4vTO #F
{ ` =dD6r
nSplitter = nCount; PaV[{CD
} &oiX/UaY
} @Fqh]1t
(6z^m?t?
exV6&bdu
/* hC<X\yxe
**Utility.java 'P}"ZHW
*/ +V1EqC*
package NetFox; 8YraW|H
m_~ p G
qAm$yfYs`
public class Utility { k(o[T),_%0
)gV+BHK
y4)M,+O5
public Utility() />q=qkdq0
{ !U}A1)
OYC4iI
+GI[ Kq
} pOD|
nWN~G
//线程睡眠 V4qHaG
public static void sleep(int nSecond) ]>/YU*\
{ !`\W8JT+
try{ Dqe)8 r
Thread.sleep(nSecond); y?<[g;MuT
} VgZ<T,SuW
catch(Exception e) Gk,{{:M:5
{ MLY19;e
e.printStackTrace (); >1a-}>r
} Vj4 if@Z
} _`/0/69
wQ!~c2a<8
//日志 ~wDmt
public static void log(String sMsg) |K'{R'A
{ %cO;{og M
System.err.println(sMsg); m(nlu
} N<hbV0$%
vX)6N#D!
,oIZ5u{#,
public static void log(int sMsg) +@]1!|@(
{ nSsVONHfa
System.err.println(sMsg); s8}:8
} M ^ZoBsZ
} Y_>z"T
2iI"|k9M
ogMLv}
/* *]z.BZI:
**TestMethod.java V|}9d:&O
*/ +^gh3Y
package NetFox; t2p/NIn
p]`pUw{
J=*y>Zt-b
public class TestMethod { g}Hk4+
tzi+A;>c(v
p1v:X?
public TestMethod() 0-0 )E&2
{ ///xx/weblogic60b2_win.exe #"ayq,GC<
try{ |/arxb&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); aen(Mcd3bg
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8jqt=}b
SiteFileFetch fileFetch = new SiteFileFetch(bean); pW:h\}%`n
fileFetch.start(); jCW>=1:JGY
} (&PamsV*8
catch(Exception e){e.printStackTrace ();} 'nP'MA9b;a
^K@r!)We
6\ux;lksn*
} w?C_LP
D\(,:_ge
78+H|bH8
public static void main(String[] args) *IGxa
{ =d~]*[8
new TestMethod(); ifTVTd7O
} |rdG+>
} &-<"HW
点击下载更多相关资料