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)); ra@CouR^c{
} u{sb^cmy
for(int i=0;i<nEndPos.length-1;i++) oykb8~u}}
{ V1Gnr~GM
nEndPos = nStartPos[i+1]; w xaMdA
} fgA-+y
nEndPos[nEndPos.length-1] = nFileLength; <1QXZfQ"
} 7T t!hf
} (Nv-wU
Q{L:pce-
O=(F46 M
//启动子线程 >X'-J{4R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kP ,8[r
for(int i=0;i<nStartPos.length;i++) LROrhO
{ Ro4!y:2|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), '=xO?2U-Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,Q.[Lc=w
nStartPos,nEndPos,i); rY8(`a
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); rBi6AM/
fileSplitterFetch.start(); 2##mVEo.(
} jbUg?4k!
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0)7v_|z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); fEiNHVx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", *YGj^+
nEndPos = " + nFileLength); B-$zioZ
// fileSplitterFetch[nPos.length-1].start(); &9z&#`AY]>
=iPQ\_ON@
k${F7I(Tb
//等待子线程结束 9, 792b
//int count = 0; Wy$Q!R=i
//是否结束while循环 GJuU?h#:/{
boolean breakWhile = false; O,KlZf_B
yAVt[+0
oRCD8b?
while(!bStop) gJBk&SDgtP
{ cK+)MFOu+
write_nPos(); 7PI|~Ifi
Utility.sleep(500); \[x4
breakWhile = true; 3Kum
Jz\'%O'
ALiXT8q
for(int i=0;i<nStartPos.length;i++) Pz1pEyuL
{ 0>m-J
if(!fileSplitterFetch.bDownOver) kfBVF%90
{ oToUpkAI
breakWhile = false; `'5(4j
break; T'l >$6
} `Q*L!/K+
} [=-?n6
if(breakWhile) 4*_9Gl
break; =LS?:Mhm
-Vk+zEht
]w(i,iJ
//count++; .Kr?vD^nG
//if(count>4) 41WnKz9c
// siteStop(); x(7K=K']
} <5A(rDij
-U(T
Zycu3%JI
System.err.println("文件下载结束！"); HP2]b?C
} auqM>yx
catch(Exception e){e.printStackTrace ();} =)(o(bfSKr
} g6k@E,cI_
# &o3[.)9
|Z<NM#1
//获得文件长度 1y l2i|m+
public long getFileSize() 6{O#!o*g
{ ,+p&ZpH
int nFileLength = -1; " mKMym2
try{ E)(`Z0
URL url = new URL(siteInfoBean.getSSiteURL()); o]NL_SM_
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ^$][ah
httpConnection.setRequestProperty("User-Agent","NetFox"); -25#Vh
;OYwZ
^q"wd?((h
int responseCode=httpConnection.getResponseCode(); -t9oL3J
if(responseCode>=400) %iPu51+=
{ Isq3YY
processErrorCode(responseCode); 'e6W$?z
return -2; //-2 represent access is error MDkIaz\U
} ixJUqo
;F&wGe
0w >DU^+
String sHeader; Q^Ln`zMe
bG&qgbN>
Qv=Z
for(int i=1;;i++) :OZhEBL&b
{ VsMNi#?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); !'MD8
//Utility.log(in.readLine()); 1e+?O7/
sHeader=httpConnection.getHeaderFieldKey(i); VA%i_P,
if(sHeader!=null) Y'~&%|9+T
{ 18HHEW{
if(sHeader.equals("Content-Length")) !Yf0y;e|:
{ #e=^[E-yE
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); sg2C_]i,H
break; j%h Y0
} CUG<v3\
} M:$nL
else 7L6M#B[)e5
break; ZSSgc0u^?
} D-!%L<<
} ~e8n yB
catch(IOException e){e.printStackTrace ();} ,m8*uCf
catch(Exception e){e.printStackTrace ();} ~k(Ez pn#
e-CW4x
m t^1[
Utility.log(nFileLength); BSf"'0I&
Qa%SvA@R
w1b <>A?87
return nFileLength; SAJ=)h~
} UXJl;Mb
n}?G!ySg
~dLZ[6Z
//保存下载信息（文件指针位置） '1 $({{R
private void write_nPos() <hbbFL}|%
{ nE;gM1I
try{ IycxRig
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~=ktFuEa
output.writeInt(nStartPos.length); Biy 9jIWI
for(int i=0;i<nStartPos.length;i++) R2`g?5v
{ A~V\r<N j
// output.writeLong(nPos); Se8y-AL6x>
output.writeLong(fileSplitterFetch.nStartPos); Qknc.Z}
output.writeLong(fileSplitterFetch.nEndPos); sD+G+
} ^nF$<#a
output.close(); dDbC0} x/
} Hrnql
catch(IOException e){e.printStackTrace ();} xk8p,>/
catch(Exception e){e.printStackTrace ();} O$/swwB!
} z:5ROlk0
F4%[R)
Dys"|,F
//读取保存的下载信息（文件指针位置） e~;)-Z
private void read_nPos() MlE~gCD
{ yZ$;O0f&&
try{ 3+5\xRq
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); J*X.0&Toc
int nCount = input.readInt(); Xy<f_
nStartPos = new long[nCount]; FF~4y>R7u
nEndPos = new long[nCount]; OZm[iH
for(int i=0;i<nStartPos.length;i++) wR4u}gb#q
{ #!,`EU
nStartPos = input.readLong(); /exl9Ilt]
nEndPos = input.readLong(); $yFuaqG`Wo
} NV4W2thYo
input.close(); 'a?.X _t
} k.[) R@0%
catch(IOException e){e.printStackTrace ();} rxp9B>~
catch(Exception e){e.printStackTrace ();} G%jJ>T4
} , %O3^7i
kQlcT"R
x>"JWD
private void processErrorCode(int nErrorCode) A!Ct,%
{ 6_K#,_oZ
System.err.println("Error Code : " + nErrorCode); S_VncTIO
} @SG"t,5s
Rbc2g"]
.x?zky^
//停止文件下载 "d>g)rvOc
public void siteStop() H6S vU
{ 4qXRDsbCf
bStop = true; Rn_W|"
for(int i=0;i<nStartPos.length;i++) i3&B%JiLX
fileSplitterFetch.splitterStop(); 1\{U<Oli
xjq7%R_,
YGV#.
} #33RhJu5,
} ^*ezj1
//负责部分文件的抓取 gIM'bA<~
**FileSplitterFetch.java 15T[J%7f
*/ )'dH}3Ba
package NetFox; =/QU$[7X(
;(0$~O$3u
.C;_4jE
import java.io.*; ?r E]s!K
import java.net.*; %x8`fm
dtnet_j
HGQ?(2]8$
public class FileSplitterFetch extends Thread { C"^hMsU8
r{2].31'
xm,`4WdG
String sURL; //File URL ?-::{2O)
long nStartPos; //File Snippet Start Position ,ibPSN5Ca
long nEndPos; //File Snippet End Position dJ%Rk#?;A
int nThreadID; //Thread's ID b'oGt,
boolean bDownOver = false; //Downing is over 1H,tP|s
boolean bStop = false; //Stop identical X*9N[#wu6
FileAccessI fileAccessI = null; //File Access interface $n#Bi.A j
T<e7(=
1.95 ^8
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YaNH.$.:
{ ;y~{+{{Ow
this.sURL = sURL; y-\A@jJC5
this.nStartPos = nStart; g?[&0r1
this.nEndPos = nEnd; {pb9UUP2
nThreadID = id; ^2C /!Y<
fileAccessI = new FileAccessI(sName,nStartPos);//定位 4o4 =
} MYhx'[4[3
7.e7Fi{
%t`SSW7I
public void run() pPyvR;NJ
{ mYh5#E41J
while(nStartPos < nEndPos && !bStop) oO#xx)b
{ I& M36f
&`yOIX-H_
^6aS]t
try{ 2\nN4WL 5.
URL url = new URL(sURL); IObx^N_K
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1O7]3&L@
httpConnection.setRequestProperty("User-Agent","NetFox"); ;;?vgrz
String sProperty = "bytes="+nStartPos+"-"; .B'UQ|NR
httpConnection.setRequestProperty("RANGE",sProperty); ',JrY)
Utility.log(sProperty); ,'C30A*p
1^L`)Up
(rr}Pv%yb
InputStream input = httpConnection.getInputStream(); j1puB
//logResponseHead(httpConnection); Zn@W7c,_I
h@~:(:zU$
JAlU%n?R
byte[] b = new byte[1024]; w{3Q( =&
int nRead; W}XYmF*_?
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tx0Go'{
{ ~^I\crx,U%
nStartPos += fileAccessI.write(b,0,nRead); i s L{9^
//if(nThreadID == 1) {)V?R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); k7^R,.c@
} M%$DT
JFM"ii{8
a-]hW=[
Utility.log("Thread " + nThreadID + " is over!"); N%9h~G
bDownOver = true; e,f ;
//nPos = fileAccessI.write (b,0,nRead); t`"^7YFS>
} 9W*.lf
catch(Exception e){e.printStackTrace ();} fyI_
} b'velj3A
} ajn-KG!A
F=XF]
Fr-[UZ~V
//打印回应的头信息 M h`CP
public void logResponseHead(HttpURLConnection con) '#v71,
{ #gh p/YoTq
for(int i=1;;i++) _6;<ow
{ ZjqA30!
String header=con.getHeaderFieldKey(i); Kw)KA^KF
if(header!=null) cV-i*L4X
//responseHeaders.put(header,httpConnection.getHeaderField(header)); OI+E (nA
Utility.log(header+" : "+con.getHeaderField(header)); 3&es]1b
else Qi_&aU$>lM
break; tNU-2r
} 4=xq:Tf
} FQROK4x%"
]9*;;4Mg
@DuK#W"E u
public void splitterStop() zmiZ]uq
{ A2NF<ZsD
bStop = true; g6%Z)5D]!
} h%TLD[[/jr
%v{1#~u
ZYcd.?:6
} PK4`5uT
xx }GOY.J
M4KWN'
/* SdJ/4&{ !
**FileAccess.java 'e@=^FC
*//文件访问(定位，写) x6;j<m5Mjx
package NetFox; Dx-KMiQ,"(
import java.io.*; 5f^>b\8+ |
gsPl _
DG[%Nhle
public class FileAccessI implements Serializable{ PB9/m-\H
hO#t:WxFI
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 [ohBPQO
RandomAccessFile oSavedFile; A&,,9G<
long nPos; R^n@.^8s
F[Q!d6
a{'Z5ail
public FileAccessI() throws IOException yz\c5
{ * R d#{Io7
this("",0); xHo&[{
} SDYv(^ f ,
uD9|.P}
F|+W.9
public FileAccessI(String sName,long nPos) throws IOException "D][e'
{ ^2JpWY:|7
oSavedFile = new RandomAccessFile(sName,"rw"); :I1_X
this.nPos = nPos; MYLsHIPC
oSavedFile.seek(nPos); l=}~v
} JkQ\)^5v
'5KeL3J;
89~ =eY
public synchronized int write(byte[] b,int nStart,int nLen) &miexSNeF
{ en*d/>OVJ
int n = -1; 0N:XIGFa
try{ !CUoHTmB
oSavedFile.write(b,nStart,nLen); nV_8Ke
n = nLen; E=]4ctK
} <Fz~7WVd
catch(IOException e) od' /%
{ [ ho(z30k
e.printStackTrace (); .dMVoG5
} t.Nb?/
%?Y[Bk3p
_<c$)1
return n; #/2$+x
} [K/m
0\9K3
PxFWJ?=
} N_pUv
p>vU?eF
IuF_M<d,
/* cvd\/pG)
**SiteInfoBean.java 4QOEw-~w&s
*/ [BBEEI=|r
package NetFox; u+H; @
X1{[}!
e=vsuqGT
public class SiteInfoBean { ew _-Eb
zq+o+o>xo
Ian[LbCWB
private String sSiteURL; //Site's URL 66x?A0P
private String sFilePath; //Saved File's Path ".^VI2T
private String sFileName; //Saved File's Name m%;D
private int nSplitter; //Count of Splited Downloading File &8.NT~"Gg
5tjP6Z`!9`
8to8!(
public SiteInfoBean() uiq^|5Z
{//nSplitter的缺省值为5 i) E|bW;
//default value of nSplitter is 5 /sM~Uq?
this("","","",5); fXI:Y8T
} nOx4<Wk&
=K'cM=WM6
zOg7raIa
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ()&~@1U
{ CLvX!O(~
sSiteURL= sURL; r.7$&BCng
sFilePath = sPath; ODZ|bN0>
sFileName = sName; Q.K,%(^;a
this.nSplitter = nSpiltter; #\=FO>
!r<pmr3f@7
@;"|@!l|
} V:joFRH9
Zu7)gf
ui?
public String getSSiteURL() LGn:c;
{ 'dn]rV0(C
return sSiteURL; 2'w?\{}D
} 1jcouD5?H
E 7{U|\
~A\GT$
public void setSSiteURL(String value) F%RRd/'
{ yK=cZw%D
sSiteURL = value; 5?x>9Ca
} x<ZJb
XuFYYx~ ^3
p^w;kN
public String getSFilePath() JJN.ugT}1
{ vQ 6^xvk]
return sFilePath; n"c[,k+R`U
} ?Wlb3;
{ttysQ-
MDnua
public void setSFilePath(String value) (,0(
{ 8<QdMkI
sFilePath = value; "y}--
} !$gR{XH$]
AP 2_MV4W
8}O lL,fP
public String getSFileName() p8Qk'F=h
{ vdc\R?
return sFileName; rlOAo`hd
} ia!y!_L\'
OrY/`+Cog
r@H /kD
public void setSFileName(String value) nFHUy9q
{ @@Kp67Iv
sFileName = value; EE06h-ns
} 2} /aFR
NJWA3zz
.ypL=~Rp
public int getNSplitter() Ot_]3:`J~
{ wd8l$*F*
return nSplitter; B"1c
} rr],DGg+B]
6H.0vN&
PUMXOTu]
public void setNSplitter(int nCount) H)kwQRfu
{ |6sp/38#p
nSplitter = nCount; 823Y\x~>
} U)]oO
} ?jv/TBZX4
N2^=E1|_
MzdV2.
/* NRs13M<ftf
**Utility.java JE"x
*/ AUG#_HE]k
package NetFox; 6jD=F ^jw
oGnSPI5KGC
4#MtF'J
public class Utility { y@S$^jk.
k_#ak%m/
{#vgtgBB
public Utility() gV's=cQ
{ ~d.Y&b
XJ;57n-?
J/y83@
} hR?{3d#x2
hn GZ=
//线程睡眠 cA?W7D
public static void sleep(int nSecond) I5p? [
{ Qz1E 2yJ
try{ UcHJR"M~c
Thread.sleep(nSecond); W' VslZG
} Naf0)3q>!
catch(Exception e) ~Fcm[eoC
{ k(nW#*N_
e.printStackTrace (); l_d5oAh
} $bR~+C
} pz}.9 yI8
-`h)$&,
//日志 &DX! f
public static void log(String sMsg) <)H9V-5aZ
{ .uZ3odMlx
System.err.println(sMsg); +mj y<~\
} *w\W/Y
B~ GbF*j
.|70;
public static void log(int sMsg) i[3'ec3
{ aB&&YlR=n<
System.err.println(sMsg); UB@+ck
} +I|vzz`ZVr
} 7Ovi{xd@
\r+ a GB
ea 'D td
/* }&J q}j
**TestMethod.java 'zTLl8P
*/ 1>h]{%I
package NetFox; <\^8fn
VY4yS*y
c-5)QF) z
public class TestMethod { ZBp/sm
H<,gU`&R
\_f(M|
public TestMethod() +ye3HGD
{ ///xx/weblogic60b2_win.exe n/:33DAB
try{ @*((1(q
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8<Av@9 *}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); oUU1+F-
SiteFileFetch fileFetch = new SiteFileFetch(bean); E:nF$#<'N
fileFetch.start(); zQd 2
} k5pN
catch(Exception e){e.printStackTrace ();} [7Oe3=
N`e[:[
zK@@p+n_#.
} (*iHf"=\
U>N1Od4vTO
2BwO!Y[
public static void main(String[] args) ,k3FRes3
{ }qD\0+`qi
new TestMethod(); gg2(5FPP
} 4o[{>gW
} pEA:L$&
点击下载更多相关资料