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)); &hSnB~hi
} _mIa8K;
for(int i=0;i<nEndPos.length-1;i++) q\\8b{~
{ 4Zv.[V]iOO
nEndPos = nStartPos[i+1]; /8P4%[\
} WI*^+E&=*
nEndPos[nEndPos.length-1] = nFileLength; \]L::"![?
} [[/ }1%
} mG}^'?^K
m11"i=S"
-Fp!w"=T
//启动子线程 LV[66<T
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; <Y}"D Yt
for(int i=0;i<nStartPos.length;i++) p[af[!
{ }(f.uN_v
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *<|~=*Ddf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), @&i#S}%/
nStartPos,nEndPos,i); zezofW]a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); " kE:T.,
fileSplitterFetch.start(); lzr>WbM{{p
} xy-$v
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), "2vNkO##
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .Y^d9.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )$lSG}WD
nEndPos = " + nFileLength); ,\m;DR1
// fileSplitterFetch[nPos.length-1].start(); :e0R7sj
laD.or
N$ qNe'b
//等待子线程结束 f<s'prF
//int count = 0; l7D4`i<F
//是否结束while循环 L_.xr ?
boolean breakWhile = false; "OS]\-
YQB]t=Ha
x]%4M\T``
while(!bStop) Gg3?2h"d
{ $&n240(
write_nPos(); 9+N._u
Utility.sleep(500); +*:x#$phx
breakWhile = true; !7,K9/"
2os6c te
S7#^u`'Q_^
for(int i=0;i<nStartPos.length;i++) )l[7;ZIw$
{ DoCQFSL
if(!fileSplitterFetch.bDownOver) &]"_pc/>m
{ i}$N&
breakWhile = false; q=E}#[EgY
break; $U"P+
} *"wD&E?
} Ph!KL\
if(breakWhile) U7f&N
break; Ie`SWg*WL
HS5Ug'\446
/O(;~1B
//count++; \.{pZMM
//if(count>4) Z+"E*
// siteStop(); ^&G O4u
} tWX+\ |
R2H\;N
IpaJ<~ p
System.err.println("文件下载结束！"); U0|j^.)
} 2sd=G'7!
catch(Exception e){e.printStackTrace ();} ReGO9}
} V@+<,tjq
DRBYH(
BS<>gA R;/
//获得文件长度 Zkb,v!l
public long getFileSize() Lw2YP[CR
{ abk:_
int nFileLength = -1; 0wE8GmG
try{ $Ln2O#
URL url = new URL(siteInfoBean.getSSiteURL()); 2QuypVC ]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Nm:|C 3_I
httpConnection.setRequestProperty("User-Agent","NetFox"); [#@p{[?r
8-g$HXqs_#
DrCfC[A~]
int responseCode=httpConnection.getResponseCode(); =L; n8~{@y
if(responseCode>=400) h|/*yTuN.y
{ GPhwq n{
processErrorCode(responseCode); K v>#
return -2; //-2 represent access is error 7QL) }b.H
} m5Laq'~0_
o _,$`nEJ
+WEO]q?K
String sHeader; 93p9?4;n-
{~p %\
&)'kX
for(int i=1;;i++) Ei(`gp
{ =VI`CBQ/Um
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ~|d?o5W
//Utility.log(in.readLine()); !Q/O[6
sHeader=httpConnection.getHeaderFieldKey(i); +z/73s0~
if(sHeader!=null) w\Eve:
{ _f2iz4
if(sHeader.equals("Content-Length")) g8@i_
{ &7y1KwfXn
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %;XuA*e
break; `];[T=
} JU`'?b
} |P?B AWYeQ
else O#Ax P}
break; sBG(CpQ
} !{=%l+^.
} OpX
catch(IOException e){e.printStackTrace ();} sU3V)7"
catch(Exception e){e.printStackTrace ();} 8i 'jkyInT
;iI2K/ 3
Y7I
Utility.log(nFileLength); /u1zRw
]V7hl#VO
Xpz-@fqKdf
return nFileLength; AyXKhj#Ml
} IaqN@IlWb
d~s-;T
N@ tb^M
//保存下载信息（文件指针位置） <^$b1<@
private void write_nPos() )n61IqrW
{ fC:\Gh5
try{ j[ YTg]
output = new DataOutputStream(new FileOutputStream(tmpFile)); &%51jM<
output.writeInt(nStartPos.length); 6h"?3w
for(int i=0;i<nStartPos.length;i++) [-}%B0S**
{ )u:8Pv
// output.writeLong(nPos); 6EGEwx
output.writeLong(fileSplitterFetch.nStartPos); 4SO{cst
output.writeLong(fileSplitterFetch.nEndPos); c=mFYsSv
} D#(L@{vC
output.close(); o{,(`o.1O
} ov}{UP]a?
catch(IOException e){e.printStackTrace ();} nsn,8a38
catch(Exception e){e.printStackTrace ();} 6/C
} g4932_tC
:~(^b;yhZ
V3nv5/6
//读取保存的下载信息（文件指针位置） r+obm)Qtp
private void read_nPos() Q 7?4GxMj
{ Msdwv.jM
try{ !T1i_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); dv>zK#!
int nCount = input.readInt(); x@x@0k`A2
nStartPos = new long[nCount]; sVf7g?
nEndPos = new long[nCount]; 3@A k6Uh
for(int i=0;i<nStartPos.length;i++) Lf<9GYNy>`
{ b?^<';,5
nStartPos = input.readLong(); jP]'gQ!-w
nEndPos = input.readLong(); 4WnxJ]5`
} Y`RfE
input.close(); "R]K!GUU
} iSax-Mc
catch(IOException e){e.printStackTrace ();} ^u<+tV
catch(Exception e){e.printStackTrace ();} Mqy`j9FbL
} smNr%}_g
a+Nd%hoe
{hR23eE)#
private void processErrorCode(int nErrorCode) )FCqYCfk
{ ]].21
System.err.println("Error Code : " + nErrorCode); y%AJ>@/;
} U3QnWPt}>
F3'G9Xf8Q=
Fx\Re]~n
//停止文件下载 n40Z
public void siteStop() f#+ h_1#
{ h)8_sC
bStop = true; "+60B0>sc
for(int i=0;i<nStartPos.length;i++) C,rZ}-
fileSplitterFetch.splitterStop(); r~t7Z+PXF
1x)%9u}
}8e%s;C
} |F`'m":$m
} :'=C/AL
//负责部分文件的抓取 w5Z3e^g
**FileSplitterFetch.java ZG|T-r;~
*/ cR} =3|t
package NetFox; 9p<l}h7g
Gz:a1-x
:|TBsd|/x
import java.io.*; w4mL/j
import java.net.*; 8Sa<I.l
zrM|8Cu
C0wq
public class FileSplitterFetch extends Thread { Zuf&maa S
ho. a93
Nt?B(.G
String sURL; //File URL t/w>t! q
long nStartPos; //File Snippet Start Position 8?!Vr1x
long nEndPos; //File Snippet End Position k,J?L-F
int nThreadID; //Thread's ID +X%yF{^m(
boolean bDownOver = false; //Downing is over mvxvX!t
boolean bStop = false; //Stop identical t1S\M%?
FileAccessI fileAccessI = null; //File Access interface z#b6 aP
;pJ7k23(
\uH;ng|m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M*Xzr .6
{ 6IA~bkc}
this.sURL = sURL; "#%T*c{Tf0
this.nStartPos = nStart; IN"qJ3<k
this.nEndPos = nEnd; VlH9ap
nThreadID = id; AiuF3`Xa
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y!j1xnzki
} O\?ei+(H7
G9jtL$}E<
>*&[bW'}?
public void run() YGB|6p(
{ }0 Z3Lrv
while(nStartPos < nEndPos && !bStop) 0X;Dr-3<
{ g_`8K,6ln
aE+E'iL
lxbZM9A2
try{ Xv9CD
URL url = new URL(sURL); mYZH]oo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V'8 (}(s/
httpConnection.setRequestProperty("User-Agent","NetFox"); Kgcg:r:
String sProperty = "bytes="+nStartPos+"-"; )57OZ
httpConnection.setRequestProperty("RANGE",sProperty); &A>J>b
Utility.log(sProperty); ?AR6+`0
Z|u_DaSrr|
) E5ax~
InputStream input = httpConnection.getInputStream(); 3=z'Ih`
//logResponseHead(httpConnection); 9,4a?.*4~
K/altyj`
g\2Y605DM
byte[] b = new byte[1024]; ,ua]h8
int nRead; H&I0\upd
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) zk?lNs
{ ZC05^
nStartPos += fileAccessI.write(b,0,nRead); nRvV+F0#
//if(nThreadID == 1) 27)$;1MT:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #+XKfumLk
} ],#9L
Te;`-EL
!5ppA
Utility.log("Thread " + nThreadID + " is over!"); *0Fn C2W1
bDownOver = true; G'!Hc6OZ
//nPos = fileAccessI.write (b,0,nRead); ezFyd'P
} XBBsdldZ
catch(Exception e){e.printStackTrace ();} Ltc>@
} dP )YPy_`
} X)\t=><<
g8^$,
yVSJn>l!
//打印回应的头信息 Hh,\>= ':
public void logResponseHead(HttpURLConnection con) j $L
{ ?'^xO:
for(int i=1;;i++) R6!t2gdKe@
{ K@+&5\y]
String header=con.getHeaderFieldKey(i); .DHPKz`W0
if(header!=null) *PD7H9m
//responseHeaders.put(header,httpConnection.getHeaderField(header)); :Z,zWk1|
Utility.log(header+" : "+con.getHeaderField(header)); .^uNzN~
else "H6DiPh.E
break; L\!Pa+Iod
} 5s8k^n"A
} ZfoI7<?33
K-sJnQ23'
%-> X$,Q :
public void splitterStop() !Vy/-N
{ !M\8k$#"n
bStop = true; rqSeh/<iD
} XXvM*"3D5
0jG8Gmh!
:D;BA
} |}=xA%)
IOomBy:
l.El3+
/* b@"#A8M
**FileAccess.java >,7-cm=.
*//文件访问(定位，写) sBt,y_LW
package NetFox; ZDMS:w.'T
import java.io.*; xbsp[0I,
m?0caLw<
Onz@A"
public class FileAccessI implements Serializable{ :;HJ3V;
<>%2HRn<u
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yp9vgUs
RandomAccessFile oSavedFile; K+p7yZJ
long nPos; XOsuRI?
B'SLyf
i_Ol vuy~
public FileAccessI() throws IOException NU"Ld+gw
{ #?u#=]
this("",0); #%5[8~&
} %OE (?~dq
K+|G9
G LU7?2`t
public FileAccessI(String sName,long nPos) throws IOException >{R+j4%
{ 4sMA'fG
oSavedFile = new RandomAccessFile(sName,"rw"); o+*7Q!
this.nPos = nPos; J;wDvt]]1
oSavedFile.seek(nPos); @` 5P^H7
} S+2we
hX4V}kj
m9Xauk$(
public synchronized int write(byte[] b,int nStart,int nLen) +@G#Z3;l!
{ p.)IdbC`B
int n = -1; >W>3w
try{ jEu-CU#:
oSavedFile.write(b,nStart,nLen); ZB+~0[C
n = nLen; JIL(\d
} T]oVNy
catch(IOException e) Yc^;?n`x
{ wDp5HZ>
e.printStackTrace (); :yxP3e%rp
} Be;l!]i
SR>(GQ,m0;
&a8%j+j
return n; $&Lw 2 c0
} _kEU=)Xe
Bi-x gq'z
Xx,Rah)X3
} ,4mb05w;d
o#uhPUZ
/JjSx/
/* br;~}GR_h
**SiteInfoBean.java =C#22xqQ.
*/ T3bYj|rh=
package NetFox; z?<Xx?Kk
\%}w7J;
|\FJ
public class SiteInfoBean { #sm@|'Q%
x~?|bnM#3
IE:;`e:\D
private String sSiteURL; //Site's URL `D $ "K1u
private String sFilePath; //Saved File's Path +?'a2pUS
private String sFileName; //Saved File's Name ]?sw<D{
private int nSplitter; //Count of Splited Downloading File b Bkg/p]
,5& Rra/
Ug#EAV<m
public SiteInfoBean() woUt*G@
{//nSplitter的缺省值为5 K!a7Hg
//default value of nSplitter is 5 @yNCWa~N
this("","","",5); 7*eIs2aY
} LS/ZZAN u
SoHw9FtS
^tL]QE?|
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |Hv8GT
{ R^6]v`j;
sSiteURL= sURL; uoq|l
sFilePath = sPath; iw^"?:'%
sFileName = sName; nNhb,J
this.nSplitter = nSpiltter; _iH:>2p5R
{!*dk V
9w<k1j
} ^S:I38gR#q
x75 3o\u!
2,rjy|R`
public String getSSiteURL() ow9Vj$m
{ w|U7pUz
return sSiteURL; MZt&HbD-
} mr+8[0
;y.<I&
~>uu1[/
public void setSSiteURL(String value) /h,-J8[
{ T^@P.zX
sSiteURL = value; m^;A]0h+
} Uc0Sb
ug?#Oa
PG*FIRDb
public String getSFilePath() ]m\:XhI*<
{ #{~3bgY
return sFilePath; A}CpyRVCn
} Q oWjC
+ooQ-Gh
O7xBMqMf
public void setSFilePath(String value) wV"C ,*V
{ `cqZ;(^
sFilePath = value; ?>iZ){0,
} h5ZxxtGU
zfA"xD
,QHn} 3fW
public String getSFileName() ]Czq A c
{ ZIJTGa}B q
return sFileName; 8_uh2`+Bvb
} z1LY|8$G
.KxE>lJbqM
6gD|QC~;
public void setSFileName(String value) N4wMAT:h
{ du^r EMb%
sFileName = value; (=w ff5U
} etL)T":XV
0u8(*?
nXxSv~r
public int getNSplitter() ]]_H|tO
{ * TR~>|
return nSplitter; "dBCS
} zNQ|G1o
\:-N<[
Lz;E/a}s
public void setNSplitter(int nCount) ^g*/p[
{ }NETiJ"6
nSplitter = nCount; }{@RO./)[
} ?mW;%d~]
} K7$Vl"l
bHH=MLZR:
f>C|qDmT
/* o!M*cyq
**Utility.java pI{s )|"
*/ ?u8vK<2h
package NetFox; 7`6JK
YK|Y^TU^
"ktC1y1
public class Utility { &-6D'@
!;YQQ<D
#L,5;R{`
public Utility() \^%5!
{ 5s2334G
bNO/CD4
=m=utd8
} Rd.[8#7VE
QZ54Osdl
//线程睡眠 1eDc:!^SD
public static void sleep(int nSecond) CQNt
{ ^#L?HIM
try{ 6">jf #pE
Thread.sleep(nSecond); `;R|SyrX
} <ArP_! `3
catch(Exception e) c{t[iXDG
{ g$*VA} s
e.printStackTrace (); !S',V&Yb
} (FAd'$lhX}
} ;zO(bj>
GX lFS#`
//日志 Y">;2Pt;
public static void log(String sMsg) hOx">yki
{ #YSUPO%F
System.err.println(sMsg); HSOdqjR*
} ^50/.Z>
oa?eK
0Fh*8a}?b
public static void log(int sMsg) 1XO*yZF
{ hexq]'R
System.err.println(sMsg); =`X@+~%-
} )Oz( <vxw
} 'gojP
%d9UWQ
sy`:wp
/* GJItGq`)
**TestMethod.java Xze
*/ R6Cm:4m}I
package NetFox; %Ys>PzM
rQ'tab.,]
^[CD-#
public class TestMethod { kI3-G~2
d/(=q
;NRT a*
public TestMethod() iEki<e/
{ ///xx/weblogic60b2_win.exe GD'C^\EaZ
try{ 9kP!O_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); xIrpGLPSh
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); }FMl4 _}u
SiteFileFetch fileFetch = new SiteFileFetch(bean); 64\ZOG\,
fileFetch.start(); WytCc>oL
} ooIMN =
catch(Exception e){e.printStackTrace ();} $_Qo
.tN)H1.:B
=O)JPo&iwY
} Xt=&
n/8Kb.Vf
q'hV 'U
public static void main(String[] args) /@RnCjc'
{ oJ8_hk<Va8
new TestMethod(); ''BP4=r5n
} ?GFxJ6!%I
} d=qpTb;(
点击下载更多相关资料