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)); Yc=y Vh
} -6~*:zg,
for(int i=0;i<nEndPos.length-1;i++) Sn.I ]:l
{ seHwn'Jn
nEndPos = nStartPos[i+1]; b-]E-$Uz
} oHI~-{m3)
nEndPos[nEndPos.length-1] = nFileLength; XZcsx
} <Xp F
} H24g+<Tv
POH>!lHu
qS&PMQ"$
//启动子线程 U`FybP2R~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WeuV+}\b
for(int i=0;i<nStartPos.length;i++) '`"LX!"ZO
{ -_uL;9r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *IGxa
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =d~]*[8
nStartPos,nEndPos,i); n8[sR;r5f
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x@DXW(
fileSplitterFetch.start(); eno*JK
} {,IWjt &>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ?MKf=!w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); P)1@HDN==
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \q3H#1A
nEndPos = " + nFileLength); tyP-J4J
// fileSplitterFetch[nPos.length-1].start(); f*XF"@ZQV
\2_>$:UoV
edGV[=]F
//等待子线程结束 Ez?vJDd
//int count = 0; :FG}k Y
//是否结束while循环 Q)#<T]~=
boolean breakWhile = false; oCy52Bm.!
HZ8 j[kO
UgJlXB|a%2
while(!bStop) <kLY1EILM
{ 8S]Mf*~S'
write_nPos(); &M>S$+I n
Utility.sleep(500); L!S-f4^5
breakWhile = true; yel>-=Vn
d/Py,
,EZ&n[%Ko
for(int i=0;i<nStartPos.length;i++) @KOa5-u
{ e"r}I!.
if(!fileSplitterFetch.bDownOver) /lr RbZ
{ KG>.7xVWV7
breakWhile = false; !Q.c8GRUQ
break; Z6D4VZVF
} ^{6Y7T]
} FT|*~_@
if(breakWhile) iM8hGQ`
break; rFx2S
/4_}wi\
*N>Qj-KAM_
//count++; =7e8N&-nv
//if(count>4) ^]U2Jd
// siteStop(); H5&>Eny
} "3\RJ?eW:S
7e8hnTzl8<
P?9CBhN
System.err.println("文件下载结束！"); EHzZ9zH\
} '/sc `(`:0
catch(Exception e){e.printStackTrace ();} m9L+|r
} H~ks"D1
lg8~`96
T^sxR4F
//获得文件长度 YvYavd
public long getFileSize() >F+:ej
{ bzJKoxU
int nFileLength = -1; 6:B5PJq
try{ A:D\!5=
URL url = new URL(siteInfoBean.getSSiteURL()); V?_%Y<|L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LL[+QcH
httpConnection.setRequestProperty("User-Agent","NetFox"); +ixDB0"\
dH`a|SVW9
>,] #~d
int responseCode=httpConnection.getResponseCode(); ]6:5<NW
if(responseCode>=400) >p<(CVX[
{ SN]/~>/
processErrorCode(responseCode); Gi<f/xQk>
return -2; //-2 represent access is error vi5~Rd`
} 5Q%#Z L/'
Y\op9Fw
E_H1X'|qS4
String sHeader; qL'3MY.!
W2<X 5'
?-i|f_`
for(int i=1;;i++) c<H4rB
{ 3zl!x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); _p_F v>>:
//Utility.log(in.readLine()); 3/[=
sHeader=httpConnection.getHeaderFieldKey(i); KDXo9FzF
if(sHeader!=null) Iewq?s\Fo
{ Etl7V
if(sHeader.equals("Content-Length")) '@fk(~|
{ 3R{-\ZMd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1B1d>V$*
break; RF;N]A?*
} B"qG-ci
} 5=?&q 'i
else ?DRC! 9o^
break; Ee|@l3)
} >N,G@{FR
} CD[7h
catch(IOException e){e.printStackTrace ();} #ERn 8k
catch(Exception e){e.printStackTrace ();} VLO>{"{'
:?p{ga9
+]>a`~
Utility.log(nFileLength); bkM$ Qo
z N t7DK
/tUl(Fp J`
return nFileLength; 4/h2_
} Gt1Up~\s
Gg!))I+
jNyC%$
//保存下载信息（文件指针位置） .Yf h*
private void write_nPos() .U1dcL6
{ Y{O&-5H^|
try{ ex|kD*=
output = new DataOutputStream(new FileOutputStream(tmpFile)); gSGe]
output.writeInt(nStartPos.length); +p[~hM6?
for(int i=0;i<nStartPos.length;i++) gO/(/e>P
{ eyE&<:F#J
// output.writeLong(nPos); uVk8KMYU
output.writeLong(fileSplitterFetch.nStartPos); \ bhok
output.writeLong(fileSplitterFetch.nEndPos); QB.7n&u
} ]u,~/Gy
output.close(); /Mk)H d
} YL.z|{\e
catch(IOException e){e.printStackTrace ();} h49Q2`
catch(Exception e){e.printStackTrace ();} ]SPB c
} =&pbh
G8&'*7Bb
Yn#8uaU
//读取保存的下载信息（文件指针位置） PWmz7*/
private void read_nPos() 68!]q(!6F
{ SH(kUL5
try{ vr vzV
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); RasoOj$
int nCount = input.readInt(); U;nC)'~YW9
nStartPos = new long[nCount]; UQ8x#(`ak
nEndPos = new long[nCount]; L,ra=SVF
for(int i=0;i<nStartPos.length;i++) =I5XG"",
{ g\l;>
nStartPos = input.readLong(); R#`itIYh
nEndPos = input.readLong(); "a g_
} ~h@tezF
input.close(); U<t-LF3
} <2Q@^
catch(IOException e){e.printStackTrace ();} Y/^<t'o&
catch(Exception e){e.printStackTrace ();} n>4S P_[E7
} S?{5DxilO
ep?0@5D}]
'-vyQ^
private void processErrorCode(int nErrorCode) 3dbf!
{ VZ,T`8"
System.err.println("Error Code : " + nErrorCode); &8pXkD#A
} 9,W-KM
% n{W
${+.1"/[
//停止文件下载 zfZDtKq
public void siteStop() m=9N^_
{ VMWg:=~$
bStop = true; "uCQm '
for(int i=0;i<nStartPos.length;i++) lkm(3y@']A
fileSplitterFetch.splitterStop(); A!D:Kc3
.}E)7"Qi,
lP e$AI
} X\x9CA
} /kz&9FM
//负责部分文件的抓取 d.AjH9 jg
**FileSplitterFetch.java [z~Nw#
*/ K[[k,W]qb
package NetFox; .ndQ(B
LC{hoq\
SoX V
import java.io.*; mig3.is
import java.net.*; X W)A~wPBs
=5`@:!t7
~Hs{(7
public class FileSplitterFetch extends Thread { dO[4}FZ$
gp)ds^
`VsGa
String sURL; //File URL Lm|X5RVq
long nStartPos; //File Snippet Start Position X2[cR;;'
long nEndPos; //File Snippet End Position KV_Ga8hs
int nThreadID; //Thread's ID }#8uXA
boolean bDownOver = false; //Downing is over ? st#6=M
boolean bStop = false; //Stop identical 0I((UA/7Zs
FileAccessI fileAccessI = null; //File Access interface kKM%
b..$5
Z-|C{1}A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException .LhmYbQ2WE
{ CiI: uU
this.sURL = sURL; _w;+Jh
this.nStartPos = nStart; :Y>]6
this.nEndPos = nEnd; At(9)6n8
nThreadID = id; [QbXj0en$
fileAccessI = new FileAccessI(sName,nStartPos);//定位 .Qt3!ek
} gN(hv.nQ
<gLtX[v!CL
05B+WJ1
public void run() m;f?}z_\$
{ }qhK.e
while(nStartPos < nEndPos && !bStop) 5$U>M
{ kW&Z%k
qD*\}b]9I
sK0VT"7K
try{ F5+_p@!i
URL url = new URL(sURL); gi'agB^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A#S:_d
httpConnection.setRequestProperty("User-Agent","NetFox"); <UJJ],)^1A
String sProperty = "bytes="+nStartPos+"-"; 7[BL 1HI*
httpConnection.setRequestProperty("RANGE",sProperty); |nN/x<v
Utility.log(sProperty); io7U[#
C-u/{CP
Ok&>[qu
InputStream input = httpConnection.getInputStream(); HY;?z`=
//logResponseHead(httpConnection); %uVJLz
Lc<xgN+cJ
/dt!J `:
byte[] b = new byte[1024]; L59oh
int nRead; |ozoc"'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6;frIl;
{ zL'IN)7MU
nStartPos += fileAccessI.write(b,0,nRead); $af}+:'
//if(nThreadID == 1) -!,]Y10
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jHlOP,kc
} 7/_ VE
'S7@+kJ
\Z20fh2
Utility.log("Thread " + nThreadID + " is over!"); 3D{4vMmX
bDownOver = true; ^:DhHqvK
//nPos = fileAccessI.write (b,0,nRead); Pmlgh&Z
} QX.6~*m1
catch(Exception e){e.printStackTrace ();} %K'*P56
} m}[~A@qD
} N5s|a5
/Jf`x>eiH
v7FRTrqjj
//打印回应的头信息 |vN@2h(|"
public void logResponseHead(HttpURLConnection con) 8UT%:DlxQ
{ #A9_A%_.h
for(int i=1;;i++) 3 9{"T0
{ eM=)>zl
String header=con.getHeaderFieldKey(i); '0')6zW5s
if(header!=null) c48J!,jCd'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %;(|KrUN
Utility.log(header+" : "+con.getHeaderField(header)); _~ZQ b
else xPMyG);
break; _:X|R#d
} * \o$-6<
} N~; khS]
hLbT\J`I
zc/%1
public void splitterStop() >Ug?O~-
{ w<~<(5mM5;
bStop = true; }SMJD
} cbCE $
NQ!N"C3u
E`uaE=Mdq
} %Mng8r
*76viqY;dE
_lPl)8k
/* ?3,64[
**FileAccess.java Dg>'5`&
*//文件访问(定位，写) $wYuH9(
package NetFox; X!rQ@F3
import java.io.*; 8jjk?PUD8
'!^E92
vN,}aV2nq
public class FileAccessI implements Serializable{ OKZam ik~
>!Ap/{2
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 nKjeH@&#
RandomAccessFile oSavedFile; \gp,Txueb
long nPos; AO}i@YJth
YKe0:cWc
Z0"&
public FileAccessI() throws IOException Naf`hE9
{ !*?(Q6
this("",0); adO!Gs9f?
} I,<>%Z|'
\'??
Jn[q<e"
public FileAccessI(String sName,long nPos) throws IOException 85%Pq:E
{ u1;e*ty
oSavedFile = new RandomAccessFile(sName,"rw"); X(!AI|6Bt
this.nPos = nPos; VX!Y`y^a
oSavedFile.seek(nPos); ~*mOt7G
} uZ/7t(fy
N{^>MRK=5
l|vWeBs
public synchronized int write(byte[] b,int nStart,int nLen) PUE'Rr(Q
{ )7I.N]=
int n = -1; ST: v3*
try{ UN*dU
oSavedFile.write(b,nStart,nLen); 1akD]Z
n = nLen; 6)#- 5m
} rKzv8d
catch(IOException e) ayH% qp
{ //X e*0
e.printStackTrace (); E+m]aYu"
} 9B+ zJ Vte
^p"4)6p-W
KkdG.c'
return n; uP%axys
} ^<>Jw%H
y\)G7 (
2H?I'<NoC
} Bbl)3$`,
O^X[9vrW
m~Y'$3w
/* ' 1P=^
**SiteInfoBean.java xm}q6>jRV
*/ vbRrk($`
package NetFox; (>rS _#^
wRXn9
t<!+b@l5
public class SiteInfoBean { YQ8j
IqhICC1V-
7>PF~=
private String sSiteURL; //Site's URL 4f4 i1i:
private String sFilePath; //Saved File's Path O1x0[sy
private String sFileName; //Saved File's Name aCU7w5
private int nSplitter; //Count of Splited Downloading File -5V)q.Og
e;A^.\SP
;Cr_NP[8|j
public SiteInfoBean() cg(QjH"
{//nSplitter的缺省值为5 ( }]37
//default value of nSplitter is 5 #*yM2H"7,;
this("","","",5); 943I:, B
} L4YVH2`0)
JCw{ ?^F"
#<a_: m)@
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )(h&Q? Ar
{ %~#!NX
sSiteURL= sURL; r{K\(UT]!
sFilePath = sPath; {BFT
sFileName = sName; F5N>Uqr*oN
this.nSplitter = nSpiltter; [{S;%Jj*X/
?%cn'=>ZI
-yX.Jv
} CRZi;7`*1
I@3Q=14k%
=cf{f]N
public String getSSiteURL() LPEjRG,
{ T&9`?QD
return sSiteURL; 94T}iY.
} )u39}dpeu
<@u0.-]
5TXg;v#Z
public void setSSiteURL(String value) k~0#'I9
{ =4frP*H?
sSiteURL = value; PHQ{-b?4t
} $.oOG"u0]
0s860Kn
0zeUP{MQ
public String getSFilePath() !(kX~S
{ Bz~ -2#l
return sFilePath; 6RK ~Dl&g
} =E;=+eqt
\e?.hmq
w) =eMdj\o
public void setSFilePath(String value) f!5F]qP>-
{ kx|me~I
sFilePath = value; +VSZhg,Np8
} wENzlXeOP
]UK`?J=t2g
^F>4~68d
public String getSFileName() ^Vag1(hdq
{ f"Ost;7zg
return sFileName; 60`+9(^
} fph-v-cl
e Wc_N
T1l&B
public void setSFileName(String value) W;^N8ap%
{ %)pP[[h
sFileName = value; Hab!qWK`
} OZG0AX+=#
O[; +i
pPoH5CzcK
public int getNSplitter() ?K0U3V$s
{ pp(H PKs=}
return nSplitter; Oz:D.V 3~
} s>T`l
fCLcU@3W?
Gu2_dT
public void setNSplitter(int nCount) ft{W/ * +_
{ a]`itjL^
nSplitter = nCount; /Z:N8e
} >Cvjs
} \0D$Mie
1XG$ z@NN
/v5qyR7an
/* rxQ<4
**Utility.java ICk(z~D~
*/ WS5A Y @(~
package NetFox; ?RDO] I>
Ru:n~77{
KL "Y!PN:
public class Utility { 1:_=g#WH
p:B ]Ft
~u!gUJ:
public Utility() j5zFDh1(
{ Z)NrhJC
T$u~E1
7k `_#
} "r@G@pe
U M@naU
//线程睡眠 K${}r0
public static void sleep(int nSecond) zyDZ$Dhka
{ T:U4:"
try{ G[#.mD{k
Thread.sleep(nSecond); Khj=llo,
} 3)y{n%3L
catch(Exception e) z4g+2f7h-X
{ eO'xkm
e.printStackTrace (); )`<6taKx@n
} 90p3V\LO
} i(0hvV>'
BH5w@
//日志 prUHjS
public static void log(String sMsg) $R";
{ 0rcjorWI
System.err.println(sMsg); ^PC\E}
} ~Yl<S(/4
P])L8zK
dN<5JQql
public static void log(int sMsg) +lKrj\Xj
{ +5-]iKh
System.err.println(sMsg); XoJgs$3B
} 8^y=H=
} vb %T7
;,dkJ7M
iOll WkF
/* [%jxf\9jJ_
**TestMethod.java Q&gPa]z]}
*/ @HvScg*Y
package NetFox; d5:tSO
K@6`-|I
dnwdFsf
public class TestMethod { O4E(R?wd
WO@H*
8[~~gYl
public TestMethod() [^M|lf
{ ///xx/weblogic60b2_win.exe x<@kjfm5
try{ HVGr-/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); VJg,~lQN#t
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 7G"7wYc>R
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,%Z&*n
fileFetch.start(); SW#BZ3L
} |Ytg
catch(Exception e){e.printStackTrace ();} 6b<+8w
[fxuUmU
sQtf,e|p
} 5DOE3T`^Oc
oIR.|=Hk{
U@?6*,b(.
public static void main(String[] args) {`F1u?l
{ /W`$yM3
new TestMethod(); 5%P[^}
} E=kw)<X2
} )v1CC..
点击下载更多相关资料