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)); 7{VN27Fa_
} _Om5wp=:
for(int i=0;i<nEndPos.length-1;i++) R-2Abyts2
{ d7Z$/ $
nEndPos = nStartPos[i+1]; I]Z"?T
} 2Y;iqR
nEndPos[nEndPos.length-1] = nFileLength; a!&m\+?
} |T*t3}
} 3g0v,7,Zv
YdYaLTz
qy-Hv6oof
//启动子线程 %4/X;w\3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; g}BS:#$
for(int i=0;i<nStartPos.length;i++) aq9Ej]1b
{ kZcGe*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N0YJ'.=8,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), awLSY:JI
nStartPos,nEndPos,i); GwG(?_I"
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MEtKFC|p
fileSplitterFetch.start(); ]XWtw21I1
} D/z*F8'c
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &}0#(Fa`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); )>pIAYCVP
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D e$K
nEndPos = " + nFileLength); )$O'L7In&
// fileSplitterFetch[nPos.length-1].start(); 3)l<'~"z<
o%h[o9i
#BI6+rfv|
//等待子线程结束 , lBHA+@
//int count = 0; h0l_9uI
//是否结束while循环 ei[,ug'
boolean breakWhile = false; =[)2DJC
<}%gZ:Z6g
vfh\X1Ui}
while(!bStop) '=UsN_@
{ n,p \~Tu,
write_nPos(); U.ew6`'Te
Utility.sleep(500); C-(O*hK
breakWhile = true; xz}=C:s
F[X;A\
Fn;Gq-^7@
for(int i=0;i<nStartPos.length;i++) W)`H(J
{ f=>iiv
if(!fileSplitterFetch.bDownOver) h~#.s*0.F
{ Hc\oR(L
breakWhile = false; irn }.e
break; -)e(Qt#ewl
} %,udZyO3uR
} WwLV^m]
if(breakWhile) &Z+.FTo
break; NDG?Xs [2
"ZG2olOqLI
"gXvnl
//count++; #aadnbf
//if(count>4) bFfDaO<k
// siteStop(); Rts}y:44
} UJ&gm_M+kL
%vU*4mH
3`ze<K((
System.err.println("文件下载结束！"); _2xYDi
} ^E3 HY@j
catch(Exception e){e.printStackTrace ();} B,A\/%<
} '~pZj"uy
NOtwgZ-
E{'\(6z_
//获得文件长度 (=tu~ ^
public long getFileSize() 8qs8QK
{ rU7t~DKS
int nFileLength = -1; 9|>5;Ej
try{ T{Yk/Z/}?
URL url = new URL(siteInfoBean.getSSiteURL()); *35o$P46
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wtfM}MW\
httpConnection.setRequestProperty("User-Agent","NetFox"); D!bi>]Yd
<-!'V,c
)umW-A
int responseCode=httpConnection.getResponseCode(); h6e,w$IL
if(responseCode>=400) :a M@"#F
{ nY?X@avo>
processErrorCode(responseCode); n:%A4*
return -2; //-2 represent access is error !jN$U%/,%.
} X+//$J
^ANz=`N5,
mz^[C7(q'(
String sHeader; Q0TKM>
6`)Ss5jzk
u6P U(f
for(int i=1;;i++) #s-li b
{ ''CowI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); QtfLJ5vi
//Utility.log(in.readLine()); PML84*K -
sHeader=httpConnection.getHeaderFieldKey(i); ;}AcyVV
if(sHeader!=null) 2spK#0n.HV
{ mCEWp
if(sHeader.equals("Content-Length")) CdiL{zH\3
{ [.4D<}e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); V(n3W=#kky
break; N{fYO4O
} Y1 6pT
} =L}$#Y8?
else aGmbB7[BZ
break; Wr.~Ns<
} rXnG"A
} GC~N$!*
catch(IOException e){e.printStackTrace ();} +Z%8X!Q
catch(Exception e){e.printStackTrace ();} tOw[
b/eo]Id]
Jv:|J DZ'
Utility.log(nFileLength); t($z+C<
6bt{j
9;EY3[N
return nFileLength; SwmX_F#_
} A>}]=Ii/
bqUQadDB
0"=}d y
//保存下载信息（文件指针位置） x`p3I*_HT5
private void write_nPos() .y~~[QF}8
{ "RsH'`
try{ )jN fQ!?/
output = new DataOutputStream(new FileOutputStream(tmpFile)); edh<L/%D
output.writeInt(nStartPos.length); '5n=tRx
for(int i=0;i<nStartPos.length;i++) JLV?n,nF
{ NKw}VW'|
// output.writeLong(nPos); OGU#%5"<
output.writeLong(fileSplitterFetch.nStartPos); p:8]jD@}%
output.writeLong(fileSplitterFetch.nEndPos); )1]LoEdm`
} h3kBNBI )
output.close(); =|bW >y
} eR5+1b
catch(IOException e){e.printStackTrace ();} nB86oQ/S
catch(Exception e){e.printStackTrace ();} 1V1T1
} ki|w?0s
j_~lc,+m
'#x<Fo~hT
//读取保存的下载信息（文件指针位置） Q$DF3[NC
private void read_nPos() k3t2{=&'&x
{ [0hZg
try{ 7$I *ju_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); `z3"zso
int nCount = input.readInt(); BcD%`vGJ
nStartPos = new long[nCount]; e\>g@xE%
nEndPos = new long[nCount]; 2E}^'o
for(int i=0;i<nStartPos.length;i++) =;HmU.Uek%
{ @5(HRd
nStartPos = input.readLong(); `pd1'5Hm
nEndPos = input.readLong(); ;V3d"@R,
} YiPp#0T[Gx
input.close(); J*O$)K%Hx
} 'k[gxk|d2
catch(IOException e){e.printStackTrace ();} G6x2!Ny
catch(Exception e){e.printStackTrace ();} sOW,hpNW
} F`YxH*tO7
Z'z~40Bda
S~ 3|
private void processErrorCode(int nErrorCode) ]j?Kn$nv*S
{ JSm3ZP|GqJ
System.err.println("Error Code : " + nErrorCode); T89VSB~
} f7QX"p&P
SvGs?nUU
s *1%I$=@
//停止文件下载 E|Z7art
public void siteStop() R|H_F#eVn}
{ \:wLUGFl5
bStop = true; \ g[A{
for(int i=0;i<nStartPos.length;i++) 6WnGP>tc.
fileSplitterFetch.splitterStop(); 7 }sj&
yw)Ztg)
|1(9_=i'
} m=2e1wc
} /I&b5Vp
//负责部分文件的抓取 =Z(#j5TGvH
**FileSplitterFetch.java ;]^JUmxU[d
*/ ^@..\X9
package NetFox; +bK.{1
mg^\"GC*8
#`H^8/!e
import java.io.*; gJ>HFid_C
import java.net.*; Af"vSL
cZ~\jpK
'%"#]
public class FileSplitterFetch extends Thread { p,w6D,h
Ey"<hAF
wc'K=;c
String sURL; //File URL lCyp&b#(L
long nStartPos; //File Snippet Start Position XL7jUi_4:L
long nEndPos; //File Snippet End Position n`hes_{,g
int nThreadID; //Thread's ID s~6irf/
boolean bDownOver = false; //Downing is over 5K*-)F ]
boolean bStop = false; //Stop identical kY6))9 O
FileAccessI fileAccessI = null; //File Access interface -m~[z
\;A\ vQ[
D0&{iZ(
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z[wk-a+w
{ Kv:ih=?
this.sURL = sURL; Eqva] 4
this.nStartPos = nStart; aJDu_
this.nEndPos = nEnd; 6gfdXVN5
nThreadID = id; qqYH}%0dz
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Up$vBE8i]
} k]`3if5>
[]M+(8Z_P
Uq6..<#
public void run() n[/|M
{ %j=,c{`Q
while(nStartPos < nEndPos && !bStop) 7>m#Y'ppl@
{ YtrMJ"
VRoeq {
$*H>n!&
try{ LHWh-h(s
URL url = new URL(sURL); u[oYVpe)IG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); &7X0 ;<
httpConnection.setRequestProperty("User-Agent","NetFox"); >:`Y]6z
String sProperty = "bytes="+nStartPos+"-"; ca_8S8lv
httpConnection.setRequestProperty("RANGE",sProperty); UmU=3et<Wj
Utility.log(sProperty); y*6r&989
5\tYs=>b<
yXw xq(32
InputStream input = httpConnection.getInputStream(); BI=Ie?
//logResponseHead(httpConnection); g5to0
\?fl%r2
m-a_<xo
byte[] b = new byte[1024]; +* )Qi)
int nRead; 8L 9;VY^Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 1W HR;!u
{ ? F fw'O
nStartPos += fileAccessI.write(b,0,nRead); H2RNekck
//if(nThreadID == 1) ,Fg&<Be}Jx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 0r=Lilu{q
} y\@;s?QL
ASaG }h
!U/:!e`N
Utility.log("Thread " + nThreadID + " is over!"); (.!q~G
bDownOver = true; _ #l b\
//nPos = fileAccessI.write (b,0,nRead); );;UNO21+
} Z-H Kdv!d
catch(Exception e){e.printStackTrace ();} u6jJf@!ws
} (s{%XB:K
} s:cS 9A8
0tB9X9:,
Zk}e?Grc
//打印回应的头信息 rsP-?oD8)
public void logResponseHead(HttpURLConnection con) 2#1FI0,Pa*
{ $X~=M_W
for(int i=1;;i++) =W !m`
{ +.\JYH=yEr
String header=con.getHeaderFieldKey(i); ^ I,1kl~i
if(header!=null) rf1nC$Sop
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;Xgy2'3
Utility.log(header+" : "+con.getHeaderField(header)); g)&-S3\
else uD:O[H-x
break; r:Cad0xj;^
} Q:VD2<2
} ,bmTBZV
a$t [}D2
+I\bs.84
public void splitterStop() ?67j+)
{ |_[mb(<|
bStop = true; w6Tb<ja
} ieS5*@^k
q}BQu@'H
^Z:x poz,
} 6nGDoW#
N'm:V
PLo.q|%
/* Z*]n]eS
**FileAccess.java /'VCJjzZ
*//文件访问(定位，写) ocgbBE
package NetFox; ~T4=Id
import java.io.*; Z/x<U.B
(%+DE4?
&|E2L1
public class FileAccessI implements Serializable{ {/0,lic
<O\z`aA'q
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 FT(EH
RandomAccessFile oSavedFile; [V jd)%
long nPos; y'yaCf
ha8do^x
}.b[az\T
public FileAccessI() throws IOException H V
{ Y@.JW
this("",0); (uV7N7 <1
} U-n33ty`H
ax>c&%vo
(vj2XiO^+
public FileAccessI(String sName,long nPos) throws IOException zLh ~x
{ rX{|]M":T
oSavedFile = new RandomAccessFile(sName,"rw"); =h_4TpDQ
this.nPos = nPos; \v-> '
oSavedFile.seek(nPos); zRE7 w:
} Zp__
acGmRP9g
wH${q@z_
public synchronized int write(byte[] b,int nStart,int nLen) 06Hn:IT18
{ 3&?Tc|F+
int n = -1; HZK0Ldf
try{ ]-PF?8
oSavedFile.write(b,nStart,nLen); h0^V!.-5
n = nLen; <&L;9fr
} =v;-{oN!
catch(IOException e) ZA9']u%EJ
{ W>DpDrO4ml
e.printStackTrace (); +j@|D@z
} M2zfN ru
dU&.gFw1
>$Fc=~;Ba
return n; mML^kgy\N
} U<6k!Y9ny
?Y hua9
3mm`8!R
} 5W{>5.Arx)
~y|%D;
A|>C3S
/* q90S>c,
**SiteInfoBean.java NI^Y%N
*/ lMm-K%(2
package NetFox; 4 ^+hw;
ASYUKh,h
vSnb>z1
public class SiteInfoBean { %cm5Z^B1"
a<Ns C1
FQ-(#[
private String sSiteURL; //Site's URL M5x!84
private String sFilePath; //Saved File's Path pz$$K?
private String sFileName; //Saved File's Name NqwVsVL
private int nSplitter; //Count of Splited Downloading File [{{?e6J
3,F/i+@
mm{U5
public SiteInfoBean() AQiP2`?
{//nSplitter的缺省值为5 - 5k4vx N}
//default value of nSplitter is 5 OUdeQO?
this("","","",5); Ch.T}%
} "=".ne
]Z84w!z
}DM2#E`_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =:g^_Hy
{ hx2C<;s4
sSiteURL= sURL; .gPsJ?b
sFilePath = sPath; gOWyV@
sFileName = sName; mhVoz0%1X
this.nSplitter = nSpiltter; -DuiK:mp
*g,?13Q_
ZK ?x_`w
} R_N<j
?}]kIK}MC
7O9s5
public String getSSiteURL() f C^l9CRY
{ pS<b|wu?f
return sSiteURL; sTA/2d
} =3zn Ta }
@NHRuk+
XOeh![eMX
public void setSSiteURL(String value) hv"toszj\
{ 6>L.)V
sSiteURL = value; tZ@+18
} z1FbW&V
Qr<%rU^{.
jF3!}*7,
public String getSFilePath() 8x9kF]=
{ )>Q 2G/@
return sFilePath; dq8 /^1P
} 6_y|4!,:W
3'"M31iA
op|mRJBq;
public void setSFilePath(String value) ~4>Xi* B
{ &53#`WgJ
sFilePath = value; V-cuG.
} #pe{:f?
mWusRgj+8
OhW=F2OIV
public String getSFileName() >b["T+
{ 5j{@2]i
return sFileName; avpw+M6+
} @1@q6@9Tu
0`P]fL+&
7XDV=PQ[
public void setSFileName(String value) Gtg)%`
{ KyyG8;G%
sFileName = value; ,Mhe:^3
} gZjOlp
ob] lCX)
ii;WmE&
public int getNSplitter() |tg?b&QR
{ tRy D@}
return nSplitter; FR}H$R7#
} .?p}:
2&Byq
R2$U K
public void setNSplitter(int nCount) Vf?#W,5>=
{ t>wxK ,
nSplitter = nCount; @"I#b99
} BY0|exW
} YSV,q@I&1
?&"^\p
}x.)gW
/* aVP|:OAj
**Utility.java >jX UO
*/ ys/mv'#>
package NetFox; B\_u${C
~& 5&s
30_un
public class Utility { ^@Qi&g`lr?
lk +K+Ra/
DVhTb
public Utility() cY2-T#rL
{ N}Ks[2
}iSakq'
|"yf@^kdC
} S/-7Zo&w+
V./w06;0
//线程睡眠 be:phS4vz
public static void sleep(int nSecond) %EGr0R(
{ , Ln
try{ b.4Xn0-M
Thread.sleep(nSecond); vSYKe
} #tZf>zrs
catch(Exception e) B~>cNj<
{ ?4ILl>*
e.printStackTrace (); B#aH\$_U
} h_~|O[5|)
} R*@[Pg*
jBv$^L
//日志 2 1~7{#
public static void log(String sMsg) q{GSsDo-:V
{ p%"yBpSK
System.err.println(sMsg); ^v!im\ r
} z9 w&uZzi
~u0xXfv#
A,gx5!J
public static void log(int sMsg) }{8Fo4/
{ HB7(
System.err.println(sMsg); -k&{nD|
} m`$>:B
} V+qJrZ,i
g6g$nY@Jm
hoR=%pC*
/* 3l%,D: ?
**TestMethod.java M{xVkXc>
*/ @vQa\|j
package NetFox; GzFE%< 9F
Yu^H*b
ufCqvv>'
public class TestMethod { wm=RD98
ck+b/.gw`
zq;DIWPIoJ
public TestMethod() 5_)@B]~nM
{ ///xx/weblogic60b2_win.exe 5!AV!A_Jp
try{ !\0F.*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); OB6J.dF[%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); jJVT_8J
SiteFileFetch fileFetch = new SiteFileFetch(bean); l>~`;W
fileFetch.start(); nMGrG
} -2\ZzK0tM
catch(Exception e){e.printStackTrace ();} "#pzZ)Zh
nlzW.OLM
] *-;' *
} fpvvV(
!7*(!as
-|}%~0)/bH
public static void main(String[] args) dC`tN5
{ st?gA"5w
new TestMethod(); 7]|zkjgI
} Dz`k[mI
} jJ aV
点击下载更多相关资料