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)); VP[-BK[
} XDs )
for(int i=0;i<nEndPos.length-1;i++) 1T:M?N8J
{ \?uaHX`1
nEndPos = nStartPos[i+1]; I;H6E
} d#P3 <
nEndPos[nEndPos.length-1] = nFileLength; CBw/a0Uck
} EV{kd.=f
} '{=dEEi
5N "fD{v{
XOgl>1O
//启动子线程 V^fSrW]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7KIOI,qb6
for(int i=0;i<nStartPos.length;i++) L".Qf|b*
{ td!WgL,m
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V ;Kzh$^rk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?mKj+Bk2
nStartPos,nEndPos,i); *#+e_)d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3]xe7F'`
fileSplitterFetch.start(); 0I_A$Z,x
} 'PPVM@)fU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tdZ,sHY6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *lHI\5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @i'24Q[6
nEndPos = " + nFileLength); #;FHyKx
// fileSplitterFetch[nPos.length-1].start(); F7$x5h@
cpz'upVOZ
uim4,Zm{
//等待子线程结束 }YUUCq&
//int count = 0; YT7,=k_
//是否结束while循环 E^uau=F
boolean breakWhile = false; '}\{4Qst
sute%6yM
O%?TxzX;
while(!bStop) .Rt_j
{ !u~h.DrvZ
write_nPos(); G8xM]'y
Utility.sleep(500); sVP[7&vr~
breakWhile = true; lF-;h{
YT!QY@qw
SN2X{Q|*
for(int i=0;i<nStartPos.length;i++) Ar&]/X,WG
{ mD}&X7
if(!fileSplitterFetch.bDownOver) iC-WQkQY
{ N<c98
breakWhile = false; E~oQ%X~
break; #N%ATV
} ]D|sQPi]F
} JqWMO!1
if(breakWhile) 0v6(A4Y
break; 9_Tk8L#
1Xy{&Ut\
qh}M!p2
//count++; P(?i>F7s
//if(count>4) g7*cwu
// siteStop(); Z}bUvr XP
} ECHl9; +
H':dLR
.5=Qfvi*
System.err.println("文件下载结束！"); (?MRbX]@
} &1O[N*$e
catch(Exception e){e.printStackTrace ();} Abr:UEG
} GE4d=;5
-$Bom
qc^u%
//获得文件长度 zrfE'C8O
public long getFileSize() ' k~'aZ
{ 0{|ib !
int nFileLength = -1; ?^iX%
try{ Jej P91
URL url = new URL(siteInfoBean.getSSiteURL()); 5`mRrEA
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); z_fR?~$N2
httpConnection.setRequestProperty("User-Agent","NetFox"); 2w`kh=
&W/C2cpmR
=XWew*
int responseCode=httpConnection.getResponseCode(); 4u5^I;4pL
if(responseCode>=400) :ie7HF
{ CD#:*
processErrorCode(responseCode); Y9F78=Q
return -2; //-2 represent access is error SI_{%~k*B
} M$O}roOa
c-nBB
Hbogi1!al|
String sHeader; 0gNwC~IA8
I}oxwc
[\N,ow,n
for(int i=1;;i++) b 62 o
{ rAqg<fR*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); (1e;7sNG@
//Utility.log(in.readLine()); + >o/Ob
sHeader=httpConnection.getHeaderFieldKey(i); F5Ce:+h
if(sHeader!=null) =\s(v-8
{ *yAC8\v
if(sHeader.equals("Content-Length")) rg U$&O
{ /'U/rjb_h{
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); /7Z0|Zw]
break; #5HJW[9
} 5A]IiX4Z
} Zf;1U98oC
else 75vd ]45as
break; hg7`jE&2
} d!) &@k
} ,sPsL9]$
catch(IOException e){e.printStackTrace ();} rtcY(5Q
catch(Exception e){e.printStackTrace ();} 9ls<Y
FY"!%)TV
= !D<1<
Utility.log(nFileLength); H?8uy_Sc
\~ O6S`,
2d+IROA
return nFileLength; )W9$_<Z
} @ -pi
CFD& -tED&
p1t9s N,
//保存下载信息（文件指针位置） "El$Sat`
private void write_nPos() 1fRYXqx
{ ,ZjbbBZ
try{ rlu{C4l
output = new DataOutputStream(new FileOutputStream(tmpFile)); W&`_cGoP
output.writeInt(nStartPos.length); k^I4z^O=-;
for(int i=0;i<nStartPos.length;i++) D6Ov]E:fa
{ mj :8ZZ
// output.writeLong(nPos); b\~rL,7(
output.writeLong(fileSplitterFetch.nStartPos); qA:CV(Z
output.writeLong(fileSplitterFetch.nEndPos); . (*V|&n
} H~RWM'_
output.close(); 2&fIF}vk>m
} vW6Pf^yJ
catch(IOException e){e.printStackTrace ();} Vf6lu)Zc1
catch(Exception e){e.printStackTrace ();} mJb>)bOl
} Er} xB~<t
'3=[xVnv
Uxx=$&#
//读取保存的下载信息（文件指针位置） OIB~W
private void read_nPos() u{=(]n
{ 0hcrQ^BB!b
try{ hBDPz1<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); /yn1MW[.
int nCount = input.readInt(); 0+IJ, ;Wx
nStartPos = new long[nCount]; 1vQf=t%lw
nEndPos = new long[nCount]; Mvoi
for(int i=0;i<nStartPos.length;i++) sAS\-c'6
{ \>nPg5OT
nStartPos = input.readLong(); SiHZco I
nEndPos = input.readLong(); k<ds7k1m
} R^P~iAO
input.close(); [0N==Ym1
} dix\hqZ
catch(IOException e){e.printStackTrace ();} 3EB8ls2
catch(Exception e){e.printStackTrace ();} 1R9hA7y&,/
} LoUi Yf
C)`ZI8
|mV*HdqU
private void processErrorCode(int nErrorCode) OtJYr1:y_
{ pgT{#[=>
System.err.println("Error Code : " + nErrorCode); &!JX
} {6'5K U*RH
=3lUr<Ze
?,NZ/n
//停止文件下载 6d"dJV.\
public void siteStop() KZeRbq2jJ
{ '#[U7(lIQ
bStop = true; A:[La#h|p
for(int i=0;i<nStartPos.length;i++) DIodQkF
fileSplitterFetch.splitterStop(); iOm1U_S
ga^O]yK
0iqa]Am
} Lhu2;F\/
} ]OZZPo
//负责部分文件的抓取 "?lirOD
**FileSplitterFetch.java yi%A*q~MT
*/ #B:J7&@fn
package NetFox; K^?yD
VcIsAK".4[
:6PWU$z$7
import java.io.*; XLp tJ4~v
import java.net.*; f]q3E[?/
-cNh5~p=
IJO`"da
public class FileSplitterFetch extends Thread { "QACQ-
|332G64K
]"q[hF*PM
String sURL; //File URL ULMG"."IH
long nStartPos; //File Snippet Start Position Sj(uc#
long nEndPos; //File Snippet End Position sIdo(`8$
int nThreadID; //Thread's ID l*("[?>I
boolean bDownOver = false; //Downing is over N:[m,U9a
boolean bStop = false; //Stop identical 3Gf^IV-
FileAccessI fileAccessI = null; //File Access interface A_T-]YQ
zMt"ST.
g"( vl-Uw
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y'Sxehx
{ EnA) Rz
this.sURL = sURL; C*ZgjFvB
this.nStartPos = nStart; Xj"/6|X
this.nEndPos = nEnd; fG;)wQJ
nThreadID = id; ;r>?V2,tm
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ui`xgR\6Rh
} =1)yI>2e%}
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8qp!S1Qnv
public void run() au}rS0)+
{ oP5G*AFUq
while(nStartPos < nEndPos && !bStop) >>Hsx2M
{ #*,Jqr2f
\bqNjlu
Pk[f_%0
try{ C\dQ6(3}\
URL url = new URL(sURL); jJ?MT#v
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TbU\qcm]]
httpConnection.setRequestProperty("User-Agent","NetFox"); `da6}Vqj:
String sProperty = "bytes="+nStartPos+"-"; p9XHYf72
httpConnection.setRequestProperty("RANGE",sProperty); (\.[pj%-O
Utility.log(sProperty); [yL%+I
<%<}];bmFL
I(P|`"
InputStream input = httpConnection.getInputStream(); 2GXAq~h@
//logResponseHead(httpConnection); m7z/@b[
IK(G%dDw
uCF+Mp
byte[] b = new byte[1024]; PV(bJ7&R
int nRead; AUcq\Ys
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |OF<=GGO+
{ ;#78`x2
nStartPos += fileAccessI.write(b,0,nRead); < Upn~tH
//if(nThreadID == 1) t#MU2b
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); c)#b*k,lw<
} B~-VGT2o
ch1EF/"
./jkY7 k
Utility.log("Thread " + nThreadID + " is over!"); +cheLc
bDownOver = true; qD7(+a
//nPos = fileAccessI.write (b,0,nRead); (' /S~
} djqSW9
catch(Exception e){e.printStackTrace ();} c%>t(ce`Tl
} heZJ(mR
} KCq qwGM
Lg|j0-"N
`x~k}
//打印回应的头信息 xO9,,w47
public void logResponseHead(HttpURLConnection con) $%`OJf*k
{ )9##mUt'}
for(int i=1;;i++) JxiLjvIq
{ !sEI|47{
String header=con.getHeaderFieldKey(i); fW!~*Q
if(header!=null) . Uv7{(
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ss T o?WL|
Utility.log(header+" : "+con.getHeaderField(header)); EyI 9$@4
else Y<:%_]]
break; ktU98Bk]
} Sq/M %z5'
} ml.l( 6A
iBwl(,)?m2
:m_0WT
public void splitterStop() t<$9!"
{ ($7>\"+Tl
bStop = true; PkF B.
} QB#f'X
}h5pM`|1
.^I,C!O#
} u]@``Zb|
JMuUj_^}7
kWjCSC>jA
/* Au#(guvm
**FileAccess.java !-2nIY!
*//文件访问(定位，写) |iLeOztuE
package NetFox; ?qAX *j
import java.io.*; =R:3J"ly0
eqD%Qdx
D*Siy;
public class FileAccessI implements Serializable{ DC]FY|ff
ppR~e*rv-
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L q'*B9
RandomAccessFile oSavedFile; $V]D7kDph*
long nPos; W!4GL>9m}A
']u w,b
yb*SD!
public FileAccessI() throws IOException RSG4A>%!mI
{ U;i:k%Bzy
this("",0); cm%QV?
} @'?<92A
W~.1f1)
p W:[Q\rSj
public FileAccessI(String sName,long nPos) throws IOException {ogGi/8
{ JiDX|Q<c
oSavedFile = new RandomAccessFile(sName,"rw"); 6f?5/hq
this.nPos = nPos; 2etcSU(y>
oSavedFile.seek(nPos); Axk p
} )$P!7$C-
"6Nma)8
g4=}].
public synchronized int write(byte[] b,int nStart,int nLen) |ZJ]`qmZ
{ j{7_p$JM
int n = -1; *P$5k1
try{ P{)&#HXUVb
oSavedFile.write(b,nStart,nLen); ;pU9ov4)
n = nLen; +&O[}%W
} O#H`/z
catch(IOException e) pA!+;Y!ZB<
{ GTYGm
e.printStackTrace (); \'GX^0yK
} CmJI"
xHJ+!
d}>Nl$
return n; HOsq _)K
} {3$ge
59$mfW o>
XsQ<yeun
} X z2IAiAs'
gD _tBv
UQPd@IVu6
/* [LL"86D
**SiteInfoBean.java }qc[ysDK]
*/ )UI T'*ow
package NetFox; fhLdM
A8e b{qv
w/d9S(
public class SiteInfoBean { NX@TWBn%
I =qd\
{h&*H[Z z
private String sSiteURL; //Site's URL +m:U9K(\h
private String sFilePath; //Saved File's Path 6[aCjW
private String sFileName; //Saved File's Name <Sm=,Sw
private int nSplitter; //Count of Splited Downloading File fk*JoR.o
~b3xn T
@K4} cP
public SiteInfoBean() gO*cX&
{//nSplitter的缺省值为5 +SrE
//default value of nSplitter is 5 =H>rX 2k
this("","","",5); 0Ny0#;P
} $SG^, !!&A
H<}<f:
2i |wQU5w
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) KKGAk\X
{ #T#&qo#
sSiteURL= sURL; P6i4Dr
sFilePath = sPath; 6M"J3\ x
sFileName = sName; asQ pVP
this.nSplitter = nSpiltter; D<L]'
ujmW {()
E2X KhW
} 0Hff/~J
"Z&qOQg%3
-CtA\<7I
public String getSSiteURL() y\5V(Q\
{ w]tv<U={
return sSiteURL; R!*UU'se
} x"8(j8e
"}7K>|a
gWy2$)
public void setSSiteURL(String value) FLEf(
{ $'L(}gNv5
sSiteURL = value; 3c@Cb`w@
} S.t+HwVodO
Vfg144FG'
@,M!&l
public String getSFilePath() _m3PAD4
{ K+ufcct
return sFilePath; \ts:'
} b'Mg
5SR29Z[
<G2;nvRr
public void setSFilePath(String value) ;o%r{:lng
{ l= ~]MSwY
sFilePath = value; KSh<_`j
} kn+`2-0
jBI VZ!X
}k\a~<'X
public String getSFileName() C<qJnB:B9
{ -$dnUXFsj[
return sFileName; TeHL=\L-^
} @L{HT8utK3
6dC!&leNi
d?b2jZ$r]
public void setSFileName(String value) CWCE}WU>4
{ bC?t4-W
sFileName = value; z)43+8;
} qO&:J\d
f`/JY!uj{
_P,fJ`w
public int getNSplitter() (zk'i13#6
{ ?ohLcz
return nSplitter; d/Zt}{
} A ;Z%-x
&Vnet7LfU
*=@Z\]"?
public void setNSplitter(int nCount) WAqR70{KM
{ u"X8(\pOn
nSplitter = nCount; jpm}EOq<%
} |I)xK@7
} 9co -W+
+;FF0_
3~s0ux[
/* AGK+~EjL@
**Utility.java }-: d*YtK
*/ &[R&@l Y
package NetFox; ,dZ 9=]
>=C)\Yfu)
ou,W|<%
public class Utility { @_N -> l
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-_>c P
public Utility() 7dV^35 KP
{ '~3(s?B
8V=I[UF.1?
RM%lhDFY
} Br\/7F
wT*`Od8w
//线程睡眠 ,1^)JshZ~
public static void sleep(int nSecond) 4.H!rkMM
{ -lb}}z+/
try{ Og30&a!~F
Thread.sleep(nSecond); 7F}I.,<W
} GN=F-*2
catch(Exception e) K8284A8v
{ "=4=Q\0PT
e.printStackTrace (); Y$oBsg\v
} "TN}=^A\F
} Gp32\^H|<
b*P\a
//日志 nU`vj`K
public static void log(String sMsg) a`/[\K6
{ kIXLB!L2b^
System.err.println(sMsg); P3lNns3
} M&Ycw XV:Z
G@,qO#5&
c{FvMV2em
public static void log(int sMsg) &,NHk9.aq
{ Zh3]bg5
System.err.println(sMsg); f)"O( c
} W=F?+KgL
} ~POe0!}
(_<ruwV]`
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/* \ZCc~muR
**TestMethod.java v6oZD;;~
*/ j}0*`[c
package NetFox; |6_<4lmTxF
j q1qj9KZ
E.6^~'/
public class TestMethod { #n~/~*:i92
$R7d*\(G
5%tIAbGW
public TestMethod() 9dKrE_zK:
{ ///xx/weblogic60b2_win.exe {H"gp?Z-
try{ 9W'#4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); wond>m 3
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @X1>Wv|[
SiteFileFetch fileFetch = new SiteFileFetch(bean); OaU$ [Z'8
fileFetch.start(); 1*>a
} J5|Dduv
catch(Exception e){e.printStackTrace ();} XPWK"t01
F_V~UX1D
rl4daV&,U
} AQ+w%>G6
$lV0TCgba8
PPE:@!u<
public static void main(String[] args) M=0I 3o}J
{ 3+n&Ya1
new TestMethod(); yKfRwO[j
} A!iV iX &y
} [@>Kd`!'
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