http断点续传简单实现（java)

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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)); XDyo=A]
} gcO$T`
for(int i=0;i<nEndPos.length-1;i++) & @_PY
{ Ku uiU= (L
nEndPos = nStartPos[i+1]; xI#rnx*
} p15dbr1
nEndPos[nEndPos.length-1] = nFileLength; <}c7E3Uc
} vpdPW%B
} :f_oN3F p
0yMHU[):~
%z-so?gF
//启动子线程 -byaV;T?"
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; n;vZY
for(int i=0;i<nStartPos.length;i++) >o&%via}
{ ?8< =.,r
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I0x;rP
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), $nIE;idk
nStartPos,nEndPos,i); hcYqiM@8>
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d1t_o2
fileSplitterFetch.start(); +7 j/.R
} 7(C)vtEO:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KjF8T7%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %gSmOW2.c^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", !Z{7X ^
nEndPos = " + nFileLength); Vu4LC&q
// fileSplitterFetch[nPos.length-1].start(); \`2EfYJ{
U#PgkP[4
Fe$o*r,
//等待子线程结束 ZJhI|wRwD
//int count = 0; 9PG{>W$M
//是否结束while循环 gVJh@]8)
boolean breakWhile = false; "WXUz
-?{g{6
pX!T; Re;
while(!bStop) Ad3TD L?
{ $3ZQ|X[|+
write_nPos(); ]]}iSw'
Utility.sleep(500); Iue=\qUK^
breakWhile = true; 2,Z@<
K$:btWSm
t@+e#3P!
for(int i=0;i<nStartPos.length;i++) M_cm,|FF
{ 4@mJEi{
if(!fileSplitterFetch.bDownOver) IkA~+6UY
{ W>&*.3{v
breakWhile = false; 8NE[L#k
break; H<g8u{ $
} |DVFi2
} o"P)(;
if(breakWhile) @(N} {om
break; s9+lC!!
j b'M
"qZTgCOY2
//count++; [ws;|nh
//if(count>4) I.~=\%Z{
// siteStop(); ,qV7$u
} loBW#>
QC]<`!
zJUT<%[U
System.err.println("文件下载结束！"); m@L>6;*
} :iQJ9Hdz
catch(Exception e){e.printStackTrace ();} <1x u&Z7
} :8N by$#V
vtK.7AF
V;)+v#4{
//获得文件长度 L7xiq{t`Y
public long getFileSize() k{|>!(Ax
{ h:FN&E c}
int nFileLength = -1; !Zc#E,
try{ B7[#z{8'#
URL url = new URL(siteInfoBean.getSSiteURL()); <RH%FhT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); LUpkO
httpConnection.setRequestProperty("User-Agent","NetFox"); 4[%_Bnv#AJ
LRS,bl3}/
.+u r+"i
int responseCode=httpConnection.getResponseCode(); 2'Kh>c2
if(responseCode>=400) #BH]`A J
{ X_rv}
processErrorCode(responseCode); eE\T,u5:
return -2; //-2 represent access is error g@?R"
} ]S@DVXH
t)O]0) s
'*&V7:
String sHeader; wLE|J9t%Ea
W>b\O">
v=&xiwz}
for(int i=1;;i++) _KyhX|
{ Ar_Yl|a
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); p-!/p#
//Utility.log(in.readLine()); )lUocm
sHeader=httpConnection.getHeaderFieldKey(i); q8R,#\T*
if(sHeader!=null) ! 8Ro5),
{ q 4Ok$~"I
if(sHeader.equals("Content-Length")) }h3[QUVf%
{ *kj+6`:CPs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ox";%|PP1
break; K,P`V &m?
} ~0Zy$L/D
} N!\1O,
else EVLDP\w{
break; KO[T&#y'
} R.GDCGAL
} =*6H!bzX
catch(IOException e){e.printStackTrace ();} 9Nz}'a;?>
catch(Exception e){e.printStackTrace ();} 4>B=k
(Bpn9}F-V.
DD>n-8M@>
Utility.log(nFileLength); <p` F/p-
Dv^M/z2&[
k@>(sXs
return nFileLength; lx~C{tl2
} ys7Tq+
y^ st T^
XF@34b5(
//保存下载信息（文件指针位置） DoICf1
private void write_nPos() [8acan+ 2l
{ 9sv#TT5V
try{ 9El{>&Fs4
output = new DataOutputStream(new FileOutputStream(tmpFile)); yU~wZjw
output.writeInt(nStartPos.length); a'>n'Y~E
for(int i=0;i<nStartPos.length;i++) 4O{,oN~7
{ D7jbo[GgS
// output.writeLong(nPos); #B_H/9f(
output.writeLong(fileSplitterFetch.nStartPos); jPc,+?
output.writeLong(fileSplitterFetch.nEndPos); :C&6M79k
} Cw5B p9
output.close(); nLrCy5R:
} lgbq^d
catch(IOException e){e.printStackTrace ();} srKEtd"
catch(Exception e){e.printStackTrace ();} a:1$idj
} 6mxzE3?G
ClPE_Cfw~
52'6wwv6?
//读取保存的下载信息（文件指针位置） }Cb-7/
private void read_nPos() @FRas00)|
{ I(/*pa?m{
try{ q[. p(6:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); -f<}lhmQ
int nCount = input.readInt(); =C7<I
nStartPos = new long[nCount]; "837b/>/
nEndPos = new long[nCount]; scE#&OWF%
for(int i=0;i<nStartPos.length;i++) ? a/\5`gnN
{ I&% Z*H
nStartPos = input.readLong(); ^i@0P}K<
nEndPos = input.readLong(); eK\i={va
} 6r h#ATep
input.close(); x-q_sZ^8
} +7y#c20
catch(IOException e){e.printStackTrace ();} pqohLA
catch(Exception e){e.printStackTrace ();} O6\c1ha
} @$~;vS
))7CqN
bq}`jP~#
private void processErrorCode(int nErrorCode) Vw&#Lo
{ )3 '8T>^<K
System.err.println("Error Code : " + nErrorCode); -O $!sFmY
} E$v!Z;A
I 6L3M\+-
pMf ?'l
//停止文件下载 ]#'&x%m
public void siteStop() ahN8IV=+Gm
{ ;[:IC^9fv
bStop = true; .k,,PuP
for(int i=0;i<nStartPos.length;i++) *(Z\"o!
fileSplitterFetch.splitterStop(); GgtYO4,
Vf$$e)
~bw=;xF{3
} wF*9%K'E
} :=:m4UJb
//负责部分文件的抓取 AO(zl*4
**FileSplitterFetch.java v&sl_w/tn
*/ T#&X7!4
package NetFox; 7GJcg7s*T
NBw{
4Q,|7@
import java.io.*; @J'tPW<$
import java.net.*; j@/p: fk
xg'xuz$U
79+i4(H
public class FileSplitterFetch extends Thread { l4& l)4Rx
.OlPVMFt
R I:kp.V
String sURL; //File URL }LoMS<O-[
long nStartPos; //File Snippet Start Position NE|Q0g
long nEndPos; //File Snippet End Position }V 4u`=
int nThreadID; //Thread's ID 8\+DSA
boolean bDownOver = false; //Downing is over `~NjBtQ
boolean bStop = false; //Stop identical ehZ/J5
FileAccessI fileAccessI = null; //File Access interface vPrlRG6
D8WKy
@z`eqG,']
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @=BApuer+
{ cG1iO:
this.sURL = sURL; x+[ATZ([
this.nStartPos = nStart; #[Rs&$vQm
this.nEndPos = nEnd; rrG}; A
nThreadID = id; RW<4",
fileAccessI = new FileAccessI(sName,nStartPos);//定位 &<- S-e
} R_ )PbFw
m!3D5z]n9
uF[~YJ>
public void run() +&<k}Mz
{ 7zowvE?#
while(nStartPos < nEndPos && !bStop) 60WlC0Y~u
{ fk\]wFj
ONFx -U]
mRxeob
try{ tY#Zl 54~{
URL url = new URL(sURL); `w)yR>lqh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); XI,=W
httpConnection.setRequestProperty("User-Agent","NetFox"); CQ7NQ^3k
String sProperty = "bytes="+nStartPos+"-"; ?[)V
httpConnection.setRequestProperty("RANGE",sProperty); 7/)0{B4U'
Utility.log(sProperty); =JxEM7r
Z=]ujlD
; FHnu|
InputStream input = httpConnection.getInputStream(); 7t/Y5Qf
//logResponseHead(httpConnection); h\+8eeIl
`$vf9'\+
\$gA2r
byte[] b = new byte[1024]; =>@ X+4Kb
int nRead; 8TTj<T!N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) \~l"
{ PO,zP9
nStartPos += fileAccessI.write(b,0,nRead); 35:RsL
//if(nThreadID == 1) zT93Sb
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .eyJ<b9
} f*VXg[&\\F
JkKbw&65
8fK/0u^`d
Utility.log("Thread " + nThreadID + " is over!"); gu&W:FY
bDownOver = true; |\94a
//nPos = fileAccessI.write (b,0,nRead); n3$u9!|P
} 3#eAXIW[
catch(Exception e){e.printStackTrace ();} 3EE_"}H>
} t[MM=6|Wb
} "6v_<t`q"
n$E$@
w}e_17A
//打印回应的头信息 E%a&6W
public void logResponseHead(HttpURLConnection con) l8e)|MSh
{ $f>(TW
for(int i=1;;i++) ^)h&s*
{ +{#Z^y6&
String header=con.getHeaderFieldKey(i); ;j+*}|!
if(header!=null) xc7Rrh]}
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dV-6l6
Utility.log(header+" : "+con.getHeaderField(header)); T&}KUX~Q/
else b~(S;1NS'
break; ({D>(xN
} 6P)DM
} ,k(B>O~o
fUZCP*7>
(0rcLNk{|
public void splitterStop() 8G3.bi'q
{ )}Cf6m}
bStop = true; yw1Xxwc
} '$5d6?BC`3
}g:'K
XXeDOrb
} U/xzl4m6
L@f&71
]v:"
/* fA=Lb^,M
**FileAccess.java ezri9\Ju
*//文件访问(定位，写) Q5_,`r`
package NetFox; 15%6;K?b
import java.io.*; w{N8Y~O
Pon0(:#1
L=P8;Gj)
public class FileAccessI implements Serializable{ dCLNZq h6
/+WC6&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %ofq
RandomAccessFile oSavedFile; ,wy;7T>ODd
long nPos; Y@qugQM>
^N`KT
yN06` =
public FileAccessI() throws IOException LxiN9
{ e)3Mg^
this("",0); GoPMWbI7
} @gQ?cU7
\x5>H:\Y
ZT`" {#L
public FileAccessI(String sName,long nPos) throws IOException MJa`4[/
{ "#iO{uMWb
oSavedFile = new RandomAccessFile(sName,"rw"); TJB4N$-}A
this.nPos = nPos; e-.(O8
oSavedFile.seek(nPos); 1f?Fuw
} uzLm TmM+
`m$,8f%j6_
$U(D*0+o/
public synchronized int write(byte[] b,int nStart,int nLen) mxe\+j#
{ <TSps!(#
int n = -1; !>&G+R+k
try{ J%fJF//U
oSavedFile.write(b,nStart,nLen); a FWTm,)
n = nLen; g;:3I\L
} G/w@2lYx
catch(IOException e) OT"jV
{ B%o%%A8*g
e.printStackTrace (); =PnNett}a
} dkSd Y+Q
)]Sf|@K]
PTTUI
return n; ]{I>HA5[
} y{XNB}E
*$/Go8t4u
$jBi~QqOf
} {xP-p"?p
*Tmqs@L
gLx?0eBBA
/* T>&dPVmG,
**SiteInfoBean.java u!fZ>kS
*/ 6.a>7-K}%
package NetFox; ^{NN-
VRHS 4
x_l8&RIB*
public class SiteInfoBean { nppSrj?
R/6 v#9m7
A}3E)Qo=G
private String sSiteURL; //Site's URL r\y\]AmF
private String sFilePath; //Saved File's Path ZY;g)`E1
private String sFileName; //Saved File's Name ")NQwT}
private int nSplitter; //Count of Splited Downloading File KCqz]
7JY9#+?p>
:JXcs39
public SiteInfoBean() -vt6n1A&b
{//nSplitter的缺省值为5 UA#=K+2
//default value of nSplitter is 5 xx?0Ftuq
this("","","",5); <YWu/\{KT
} ol_&epG;ST
3;!a'[W&p
/N@NT/.M<
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) mmMiA@0
{ Yt r*"-
sSiteURL= sURL; MJKPpQ(,
sFilePath = sPath; .&K?@T4l
sFileName = sName; XD[9wd5w8
this.nSplitter = nSpiltter; lHu/pSu@k
9(bbV5}
GW9,%}l^;
} 'n?"f|G
w}29#F\]R
HS1{4/
public String getSSiteURL() kC'm |Y@T
{ %,d+jBM
return sSiteURL; U:$`M,762Z
} ubsx NCqD
= @FT$GQ
u4[JDB7tH
public void setSSiteURL(String value) XW{cC`&
{ #O'g*]j
sSiteURL = value; YKx+z[A/p
} \;"S>dg
F<)f&<5E-
@Z96902<t
public String getSFilePath() 6$fwpW
{ gX* &RsF
return sFilePath; cr^R9dv
} "7?xaGh8
1+tPd7U
^SwU]e
public void setSFilePath(String value) @*$"6!3s5
{ 7 S%`]M4;
sFilePath = value; %<h2^H\O
} V.o*`V
J!'IkC$>
w *o _s
public String getSFileName() **ls 4CE<
{ zXd#kw;
return sFileName; YIYuqtnSJ
} e"2x!(&n(
u5,vchZ
d-]!aFj|U
public void setSFileName(String value) b_@bS<wsF}
{ F<,"{L
sFileName = value; t9_&n.z
} `oE.$~'
fl*49-d
Ba n^wX
public int getNSplitter() =1mIk0H`
{ 3LVL5y7|
return nSplitter; &2W`dEv]?
} f{'NO`G
JJP!9<
y<y9'tx
public void setNSplitter(int nCount) QW%xwV?8
{ QX9['B<
nSplitter = nCount; 6%T_;"hb
} -"xC\R
} -}Rh+n`
_%aT3C}k
H]Gj$P=k
/* hud'@O"R+
**Utility.java ,9.NMFn
*/ 0fR?zT?
package NetFox; G<t_=j/r
z'EphL7r
V>Nw2u!!
public class Utility { 1sfs!b&E
' PmBNT
~hU^5R-%
public Utility() 'W[Nr
{ CWnRRZ}r
JZD&u6tB
/?6
} ;7!u(XzN
T{ /\q 5
//线程睡眠 zc>LwX}<
public static void sleep(int nSecond) m] @o1J
{ J5\2`U_FZ
try{ FsfP^a
Thread.sleep(nSecond); W1UqvaR
} N3Z6o.k
catch(Exception e) (m=F
{ W-vEh
e.printStackTrace (); ~G~:R
} L4Si0 K
} cA+O]",}
}4xz,oN
//日志 $2k9gO
public static void log(String sMsg) rE.z.r"O
{ 2iWxx:e
System.err.println(sMsg); g0RfvR
} Il<ezD{
\J{%xW>
=]sM,E,n
public static void log(int sMsg) 4)d#dy::\
{ .A<n2-
System.err.println(sMsg); ':T6m=yv
} 0 oHnam
} 7p,!<X}%
m?<5-"hz
&$_#{?dPt
/* P.]O8r
**TestMethod.java IZ+ZIR@}ci
*/ {>>Gc2UT
package NetFox; x% Eu.jj
p87VJ}
<(2,@_~@r
public class TestMethod { 'FGf#l<
8x<; AL|`
|'12Kv]#Xa
public TestMethod() </7?puVR
{ ///xx/weblogic60b2_win.exe 0'^zIL#.
try{ V?Ye^-29
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); K#'{Ko
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 8'Bik
SiteFileFetch fileFetch = new SiteFileFetch(bean); {;Y2O.lV
fileFetch.start(); tje
} A(qy>x-BI
catch(Exception e){e.printStackTrace ();} e/V8lo
GAcU8MD
{@`Z`h"N
} ik|iAWy
KN zm)O
4krK CD>|G
public static void main(String[] args) o_ SR
{ qi-!iT(fe
new TestMethod(); h8tKYm
} wr;8o*~
} F /% 5 r{
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