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)); ray3gM%JLj
} -#ZLu.
for(int i=0;i<nEndPos.length-1;i++) *`H*@2
{ pAy4%|(
nEndPos = nStartPos[i+1]; @ VWED
} c""&He4zp
nEndPos[nEndPos.length-1] = nFileLength; mh3S?Uc
} \bARp z?a
} jrQ0-D%M d
aC,adNub
p":u]Xgb
//启动子线程 #^T`vTD-
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,U\s89
for(int i=0;i<nStartPos.length;i++) 91]|4k93
{ n4{%M
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +9Tc.3vQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), EVPQe-
nStartPos,nEndPos,i); ;\pVc)\4"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); aj5HtP-
fileSplitterFetch.start(); 'gf[Wjb,%
} z8X7Y >+SA
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), .y s_'F-]0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [.}qi[=n
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t.( `$
nEndPos = " + nFileLength); n#">k%bD
// fileSplitterFetch[nPos.length-1].start(); E;a,].
*Ypn@YpSp
" aG6u^%
//等待子线程结束 ( cs
//int count = 0; >?@5>wF
//是否结束while循环 !8G)`'
boolean breakWhile = false; &Gt{9#
5&n:i,
Q5ASN"_
while(!bStop) R0Vt_7
{ (l99a&]t
write_nPos(); DzpWU8j
Utility.sleep(500); H\>{<`sD;f
breakWhile = true; @AZNF+ \W$
yI^Yh{
!,`'VQw$
for(int i=0;i<nStartPos.length;i++) I/(U0`%
{ :M"+
if(!fileSplitterFetch.bDownOver) ({E,}x
{ u !BU^@P
breakWhile = false; }k }=e
break; nYx /q
} @\g}I`_M
} x {NBhq(4
if(breakWhile) GJ%^hr`P
break; 0Q{lyu
B=cA$620
Ic0Sb7c
//count++; /GgID!8
//if(count>4) D)-LZbPa
// siteStop(); Jt[ug26
} "&={E{pQ
4;YP\{u
8!2)=8|f
System.err.println("文件下载结束！"); sOLh'x f.
} |Y!^E %*
catch(Exception e){e.printStackTrace ();} )Eozo4~
} +Csb8
JQKXbsXS
F7<mm7BGZ
//获得文件长度 -9dZT
public long getFileSize() RW&o3_Ua
{ 6y^ zC?
int nFileLength = -1; \Eh5g/,[
try{ Zv %>m
URL url = new URL(siteInfoBean.getSSiteURL()); ~<_#%R!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J&aN6l?
httpConnection.setRequestProperty("User-Agent","NetFox"); $]|3^(y``
gCghWg{S
U,U=udsi
int responseCode=httpConnection.getResponseCode(); pb97S^K[
if(responseCode>=400) A"7YkOfwH
{ WR #XPbk
processErrorCode(responseCode); D|5mNX%e
return -2; //-2 represent access is error A$wC!P|;
} Y!M0JSaM
%G!!0V!
*P'X[z
String sHeader; \aJ>?
Osqk#Oh
lj]M 1zEz&
for(int i=1;;i++) "e-Y?_S7R8
{ .JKH=?~\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); fn<dr(Dx
//Utility.log(in.readLine()); JzEg`Sn^
sHeader=httpConnection.getHeaderFieldKey(i); 4pL'c@'
if(sHeader!=null) :P-H8*n""
{ }[eUAGhDU
if(sHeader.equals("Content-Length")) 3V]dl)en%
{ PY.HZ/#d
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); uf?;;wg
break; G `|7NL
} __}SHU0R
} $ #!oejLD
else ;}Jv4Z
break; {gzQ/|}#z-
} ' wl})
} a~yiLq
catch(IOException e){e.printStackTrace ();} Kz;Ar&^`N
catch(Exception e){e.printStackTrace ();} bVcJ/+Yx|
h?TIxo:6/
N #v[YO`.
Utility.log(nFileLength); HW[&q
'_?Z{|
Kii@Z5R_?
return nFileLength; T}!9T!(HdF
} H{=]94
q&:7R .Ci
fExFpR,`
//保存下载信息（文件指针位置） 76T7<.S
private void write_nPos() ~;oXLCL0})
{ SXsszb:_
try{ B}04E^
output = new DataOutputStream(new FileOutputStream(tmpFile)); ILCh1=?{9r
output.writeInt(nStartPos.length); al#(<4sJ
for(int i=0;i<nStartPos.length;i++) ?J$k 5;
{ 2Ug_3ZuU
// output.writeLong(nPos); fOMaTnm'
output.writeLong(fileSplitterFetch.nStartPos); h_t`)]-
output.writeLong(fileSplitterFetch.nEndPos); 3fLdceT
} % (h6m${j
output.close(); ;^:8F
} k:n{AoUc
catch(IOException e){e.printStackTrace ();} L/fXP@u
catch(Exception e){e.printStackTrace ();} ;*rGZ?%*
} 5%D`y|
yPmo1|'X>d
3F,M{'q
//读取保存的下载信息（文件指针位置） ;jxX/c
private void read_nPos() 9(fh+
{ \r aP
try{ 8T"L'{ggWB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G>pedE\
int nCount = input.readInt(); 5!ngM
nStartPos = new long[nCount]; ;r2DQg"#@
nEndPos = new long[nCount]; f IV"U
for(int i=0;i<nStartPos.length;i++) C1AX
{ uNy-r`vg
nStartPos = input.readLong(); ->qRGUW
nEndPos = input.readLong(); JRBz/ j
} +_ehzo97
input.close(); 12i`82>;
} r7VBz_Q
catch(IOException e){e.printStackTrace ();} Jb{g{a/
catch(Exception e){e.printStackTrace ();} * 0K]/tn<
} @mw1__?
)*%uG{h
|j"C52Q
private void processErrorCode(int nErrorCode) hcU^!mp
{ "u^2!d
System.err.println("Error Code : " + nErrorCode); 8]&Fu3M^
} TS#1+f]9J<
=_&,^h@'3e
Z3o HOy
//停止文件下载 njd2
public void siteStop() 1f3g5y'z5
{ k4&adX@Y
bStop = true; 3B[tbU(
for(int i=0;i<nStartPos.length;i++) dDiy_Q6
fileSplitterFetch.splitterStop(); g&RhPrtl
`Zp*?
(M;d*gNr
} E_&;.hw
} ?p6@uM\Q7
//负责部分文件的抓取 8Ud.t=2
**FileSplitterFetch.java h_X'O3r
*/ ,6y.wNb:F
package NetFox; FXk*zXn6
v+EJ $
y=8KNseW|
import java.io.*; gs}&a3d7k
import java.net.*; ?b d&Av
/slCK4vFc
H^*[TX=#[
public class FileSplitterFetch extends Thread { CWZv/>,%
j}lne^ h
!]"M]tyv\
String sURL; //File URL ZLaht(`+
long nStartPos; //File Snippet Start Position 6k')12~'
long nEndPos; //File Snippet End Position hJFxT8B/
int nThreadID; //Thread's ID "pX|?ap
boolean bDownOver = false; //Downing is over 0dx%b677d
boolean bStop = false; //Stop identical @ #J2t#
FileAccessI fileAccessI = null; //File Access interface V#599-
z__{6"^
O 8l`1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 9XUYy2{G
{ Fbotn(\h@
this.sURL = sURL; %N\45nYU:
this.nStartPos = nStart; _ y'g11 \
this.nEndPos = nEnd; ;|=5)KE
nThreadID = id; 5:+x7Ed
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "kt7m
} =H-BsX?P
Yk{4 3yw
mr>E'd.'
public void run() r"L:Mu
{ 1"A"AMZf
while(nStartPos < nEndPos && !bStop) T*k{^=6"!
{ B*`[8kb,
DbI)tDi5D
"@+Z1k-8U
try{ m{*_%tjN0
URL url = new URL(sURL); "V:RKH`
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d|tNn@jN
httpConnection.setRequestProperty("User-Agent","NetFox"); L$Xkx03lz>
String sProperty = "bytes="+nStartPos+"-"; 4d`f?8vS
httpConnection.setRequestProperty("RANGE",sProperty); ktY
Utility.log(sProperty); /xg1i1Et
*Ta {
u<\Sf"fs
InputStream input = httpConnection.getInputStream(); tR=1.M96Y
//logResponseHead(httpConnection); =?M{B1;H
?YFSK
W'zI~'K
byte[] b = new byte[1024]; AGlFbc(L
int nRead; YFcMU5_F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ]7,0}q.
{ !':y8(Ou
nStartPos += fileAccessI.write(b,0,nRead); Q >h7H{c
//if(nThreadID == 1) ]<iD'=a
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wVv@
} R-Tf9?)
fn//j7 j
F{&0(6^p!
Utility.log("Thread " + nThreadID + " is over!"); x;&iLQZh
bDownOver = true; 2Zq_zvKUt
//nPos = fileAccessI.write (b,0,nRead); ;k1VY Ie}
} #%CB`l
catch(Exception e){e.printStackTrace ();} <7%#RJwe
} Zh:@AFz:R
} RLh%Y>w
#FGj)pu
MR":aT
//打印回应的头信息 [r1\FF@v,
public void logResponseHead(HttpURLConnection con) 30cb+)h(
{ "f!H[F1~
for(int i=1;;i++) zM%2h:*+{
{ EzU=q E
String header=con.getHeaderFieldKey(i); ]D>\Z(b
if(header!=null) x50ZwV&j
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +o6"Z)
Utility.log(header+" : "+con.getHeaderField(header)); N,ihQB5
else Xj6?,J
break; s=&x%0f%
} !M7727
} TwZmZE ?!
G{'`L)~3N
NW*$+u%/R
public void splitterStop() R5cpmCs@R
{ ];{CNDAL2
bStop = true; l5Q-M{w0x
} d?GB#N|+g
covK6SH
y $>U[^G[
} 5F5)Bh
DvBRK}'
[@/x
/* =eeZtj.
**FileAccess.java 4^w`]m
*//文件访问(定位，写) /kFw(l_.
package NetFox; T;Ra/H
import java.io.*; enQev?8%
?Hf8<C}3
ftqeiZ 2
public class FileAccessI implements Serializable{ ]%6XE)
<`=(Ui$fD
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 O&PrO+&
RandomAccessFile oSavedFile; jW.IkG[|
long nPos; WD'[|s\
m@c\<-P
qJJ~#W)
public FileAccessI() throws IOException &Ht5!zuW,
{ vy5SBiK
this("",0); VL@eR9}9K
} \yo)oIi[p
7,D6RP(b
>KCnmi
public FileAccessI(String sName,long nPos) throws IOException R`>z>!)
{ }woNI
oSavedFile = new RandomAccessFile(sName,"rw"); .5YW>PV
this.nPos = nPos; {#TZFB
oSavedFile.seek(nPos); cY%6+uJ1
} IaYy5Rw
2u^/yl
;fKFmY41
public synchronized int write(byte[] b,int nStart,int nLen) /: }"Zb
{ ~`CWpc:
int n = -1; 4wx_@8
try{ V%'+ ob6
oSavedFile.write(b,nStart,nLen); A:Kit_A
n = nLen; r=^?
} i{nFk',xX
catch(IOException e) p V`)
{ N:e5=;6s
e.printStackTrace (); ^yVKW5x
} *gL-v]V
`RLn)a
Ab)X/g-I@
return n; Hyz:i)2
} + Awo\;@,
U=\!`_f':
kmF@u@5M
} (GDW9:
H6%%n X
0%GQXiy
/* f-l(H="e
**SiteInfoBean.java o"e]9{+<
*/ x`gsD3C
package NetFox; Y.v. EZ
xa|/P#q
%Ig3udcY?
public class SiteInfoBean { IO]%AL(.;
`@Tl7I\
,7w[r<7
private String sSiteURL; //Site's URL m?pm)w
private String sFilePath; //Saved File's Path Ny)N
private String sFileName; //Saved File's Name Ga#5xAI{a
private int nSplitter; //Count of Splited Downloading File &! MV!9$
dhmZ3~cW>
5AO'IhpL
public SiteInfoBean() 72{Ce7J4
{//nSplitter的缺省值为5 DmpG35Jk
//default value of nSplitter is 5 N3QDPQ
this("","","",5); *Bm _
} t7qY!S (
|$a!Zx94^
HmZ*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) QcG-/_,'}
{ We*&\e+"T
sSiteURL= sURL; *B1%-
sFilePath = sPath; l5esx#([*R
sFileName = sName; zY&/^^y
this.nSplitter = nSpiltter; !1cVg ls|
"kg;fF|
`78)|a*R.
} U%E364;F
SK G!DKQ
]pP:
public String getSSiteURL() UKBaGX:v
{ QO(P_az3mg
return sSiteURL; !f!HVna
} >7I"_#x1:
A/w7(
55#s/`gd)^
public void setSSiteURL(String value) B~t[Gy
{ ?0k4l8R
sSiteURL = value; lzup! `g
} &'d3Yt
Rt2<F-gY
af<wUxM0
public String getSFilePath() -Ay=*c.4
{ <maYS2
return sFilePath; @fO[{V
} N9=1<{Z
kcN#g-0
z*B-`i.
public void setSFilePath(String value) F>/"If#
{ b'$fr6"O1
sFilePath = value; p`2w\P3;)
} oVYW'~OID
, UiA?7k
=9y&j-F
public String getSFileName() 5x/LHsr=m
{ rf]'VJg#3
return sFileName; ?A`8c R=)I
} yITL;dBy
U9eb&nd
sxFkpf_h
public void setSFileName(String value) `37$YdX
{ U+wfq%Fz
sFileName = value; $F/Uk;*d!
} yTwtGo&
%RX}sS
\GEf,%U<K
public int getNSplitter() bfl%yGkd/|
{ IMtfi(Y%F
return nSplitter; "D1u2>(
} ?3|jB?:k
0; BX
qGrUS_~q*
public void setNSplitter(int nCount) .T|1l$Jn
{ 5`H.{4@
nSplitter = nCount; !H/5Ud9
} moT*r?l
} ipdGAG
)$oboAv#
C6ry]R@
/* aq-R#q
**Utility.java B(B77SOb
*/ .qGfLvx%
package NetFox; # )]L3H<
YR/%0^M'0
T>qI,BEY
public class Utility { 8^>qzaf 8
C^8n;i9
"yA=Tw
public Utility() I@jXW>$
{ ,wPvv(b]a
xR`M#d5"
yHIZpU|(j
} |h(05Kbk
tVFydN~
//线程睡眠 M'-Z"
public static void sleep(int nSecond) V4>qR{5
{ Hu-Y[~9^L:
try{ Lk>o`<*
Thread.sleep(nSecond); ~"8D]
} |';oIYs|$
catch(Exception e) (dgBI}Za
{ S?K x:]
e.printStackTrace (); %.[jz,;)
} `<x((@#
} O\&-3#e
' zz^!@
//日志 S&Szc0-|k
public static void log(String sMsg) u-%|ZSg
{ !Un&OAy.!
System.err.println(sMsg); rS&"UH?c7
} `m7w%J.>n
|(77ao3
Iq["(!7E5
public static void log(int sMsg) SL ) ope
{ [B+]F~}@
System.err.println(sMsg); Q$lgC v^M
} ]**h`9MF
} yh:Wg$qx
q\]"}M8
vn(ji=
/* g;mX{p_@
**TestMethod.java A8oTcX_
*/ f<;w1sM\
package NetFox; -lqsFaW
c[<>e#s+;
8o%g2 P9.
public class TestMethod { rGIf/=G^r
&V77WnOY
X4I+
public TestMethod() _CImf1
{ ///xx/weblogic60b2_win.exe vzH"O=
try{ /*kc|V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i2&I<:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J@lQzRqRb
SiteFileFetch fileFetch = new SiteFileFetch(bean); "eG@F
fileFetch.start(); (N[R`LN
} /{71JqFis
catch(Exception e){e.printStackTrace ();} }8&?
#_?m.~`g[
tQ7:4._
} %|AXVv7IN>
VV$4NV&`Q
\qZ>WCp>r
public static void main(String[] args) J{qsCJiB
{ pr?k~Bn
new TestMethod(); >_'0 s
} I3,0vnE@
} LTlbrB
点击下载更多相关资料