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)); >, 9R :X(
} tQ@%3`
for(int i=0;i<nEndPos.length-1;i++) F%]ZyO9
{ jO5,PTV
nEndPos = nStartPos[i+1]; OxC8xB;`
} UG!528;7
nEndPos[nEndPos.length-1] = nFileLength; , S }
} [Zpx :r}
} 5Y3L
l!d |luqbA
s2X<b `
//启动子线程 UyUz_6J
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; +wHrS}I#g
for(int i=0;i<nStartPos.length;i++) %3:[0o={d
{ #H5i$ o
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Fmd^9K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (*K=&e0O
nStartPos,nEndPos,i); ?=dp]E{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); MB!_G[R
fileSplitterFetch.start(); n9w(Z=D\
} na4^>:r~
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *M]@}'N
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jR_o!n~5
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D^30R*gV
nEndPos = " + nFileLength); O u-/dE%
// fileSplitterFetch[nPos.length-1].start(); c{,VU.5/
%FhUjHm
nn?h;KzB
//等待子线程结束 @CUYl*.PD
//int count = 0; zgnZ72%
//是否结束while循环 z|k0${iu#
boolean breakWhile = false; qj#C8Tc7
uE]Z,`e
*q$O6B-
while(!bStop) &<>NP?j}
{ Dga;GYx
write_nPos(); (X3}&aLF
Utility.sleep(500); 11g_!X -g@
breakWhile = true; I;g>r8N-Bu
v.q`1D1=t
0zHMtC1,
for(int i=0;i<nStartPos.length;i++) z#|tcHVFT
{ G &QGQ
if(!fileSplitterFetch.bDownOver) y(fJ{k
{ G(fS__z
breakWhile = false; tYk!Y/O}
break; 2N}UB=J
} !j8 DCVb
} LZI[5tA"
if(breakWhile) ng6".u9
break; JP1XH k
+td]g9Ie
%ZR<z$
//count++; v[+ ]
//if(count>4) 4c'F.0^
// siteStop(); i!i=6m.q7
} \5pBK
+.2OZ3(
Q^{XM
System.err.println("文件下载结束！"); 7@NV|Idtd
} uz /Wbc>y
catch(Exception e){e.printStackTrace ();} .dO8I/lhV
} MfU0*nVF~
]I[\Io1
H2JKQm_
//获得文件长度 [q!/YL3%
public long getFileSize() Gpf9uj%
{ {~"fq.h!M
int nFileLength = -1; Kk\TW1w3
try{ n|N?[)^k
URL url = new URL(siteInfoBean.getSSiteURL()); o FS2*u
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M/J?$j
httpConnection.setRequestProperty("User-Agent","NetFox"); L:_GpZ_
)jPIBzMys
: =f!>_r+
int responseCode=httpConnection.getResponseCode(); _PPn =kuMa
if(responseCode>=400) EGysA{o"X
{ :%4N4| Q
processErrorCode(responseCode); wec_=EqK0
return -2; //-2 represent access is error v vzPt.ag
} ;W?mQUo:P8
(&!RX.i
Mpx98xcO
String sHeader; ^5n#hSqZ=M
%:!ILN
2)MX<prH
for(int i=1;;i++) ?D_^8\R
{ X-y3CO:&@h
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W QqOXF
//Utility.log(in.readLine()); 2Bz\Tsp
sHeader=httpConnection.getHeaderFieldKey(i); ;Qi0j<dXd
if(sHeader!=null) zhgvqg-
{ \OW.?1d
if(sHeader.equals("Content-Length")) ^u:bgwP
{ ZKTY1JW_
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 8.zYa(<2
break; :ggXVwpe
} .(%]RSBY
} cb5T-'hY
else -xVZm8y
break; tNG[|Bi#
} Y&j'2!g
} }1EtM/Ni{!
catch(IOException e){e.printStackTrace ();} SajasjE!^1
catch(Exception e){e.printStackTrace ();} e81+as
ix_&os]L_
GMlJM
Utility.log(nFileLength); Yq>K1E|
lFN|)(X
64qqJmG3
return nFileLength; (_3QZ
} ^6QzaC3
`b KJ
ENy$sS6[D
//保存下载信息（文件指针位置） AD~_n^
private void write_nPos() ~~3*o
{ :(YFIW`59
try{ tTbfyI
output = new DataOutputStream(new FileOutputStream(tmpFile)); UCo`l~K)qg
output.writeInt(nStartPos.length); rV fZ_\|
for(int i=0;i<nStartPos.length;i++) {8"Uxj_6V
{ 8[H bg
// output.writeLong(nPos); 3/ '5#$
output.writeLong(fileSplitterFetch.nStartPos); .sSbU^U
output.writeLong(fileSplitterFetch.nEndPos); pv,z$3Q
} *RmD%[f
output.close(); =wMq!mBd
} Z#%s/TL
catch(IOException e){e.printStackTrace ();} I23"DBR3
catch(Exception e){e.printStackTrace ();} ~(`&hYE
} NQcNY=
VA@
aUi^7;R&<
//读取保存的下载信息（文件指针位置） wUfm)Q#
private void read_nPos() B9wQ;[gQB
{ @D$ogU,#
try{ 48_( 'z*>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); }.D adV
int nCount = input.readInt(); x~ID[
nStartPos = new long[nCount]; AquO#A[,#
nEndPos = new long[nCount]; f\?1oMO\
for(int i=0;i<nStartPos.length;i++) =\M6s
{ n?QglN
nStartPos = input.readLong(); 0j2mTF(C
nEndPos = input.readLong(); X!6$<8+1OV
} deEc;IAo
input.close(); b!qlucAeE
} ?DE{4Ti/[
catch(IOException e){e.printStackTrace ();} akG|ic-~
catch(Exception e){e.printStackTrace ();} ,0eXg
} LK<ZF=z]Z
^O& y;5
Y?- "HK:
private void processErrorCode(int nErrorCode) uANpqT}!
{ `neo.]
System.err.println("Error Code : " + nErrorCode); 0J6* U[
} &\ K
}L @~!=q*
Bkg./iP5x
//停止文件下载 -b)3+#f
public void siteStop() `7oYXk
{ /m4Y87
bStop = true; a1EQ.u
for(int i=0;i<nStartPos.length;i++) w~3z);
fileSplitterFetch.splitterStop(); "5v^6R9e
@O|`r(le
:`c@&WF8
} ,u9>c*Ss\
} })j N 8px
//负责部分文件的抓取 <B'PB"R3y
**FileSplitterFetch.java +UiJWO
*/ = toU?:.
package NetFox; 2J (nJT"
8Y_lQfJa
}@~+%_;
import java.io.*; ]TN/n%\
import java.net.*; ]MC5 uKn
[#fz[U
zYM0?O8pJ~
public class FileSplitterFetch extends Thread { -XnOj2
$RYOj{1
R[rOzoNp0
String sURL; //File URL wRZS+^hx
long nStartPos; //File Snippet Start Position 'wWuR@e#&
long nEndPos; //File Snippet End Position hxt;sQAo{
int nThreadID; //Thread's ID c<sq0('`
boolean bDownOver = false; //Downing is over 8T8]gM
boolean bStop = false; //Stop identical PAH#yM2Ic
FileAccessI fileAccessI = null; //File Access interface =}0$|@pl
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X`fm5y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException tBETNt7
{ :\C/mT3xL)
this.sURL = sURL; Qn.3B
this.nStartPos = nStart; }*b\=AS=
this.nEndPos = nEnd; 1~E;@eK'
nThreadID = id; cqT%6Si
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RY1-Zjlb<
} \odns
$~\Tl:!#?
7X>*B~(R
public void run() DcG=u24Xy!
{ ZZ/k7(8
while(nStartPos < nEndPos && !bStop) Y~w1_>b
{ i(*fv(z
9Q1w$t~Y
P<;Puww/
try{ EKS?3z%!
URL url = new URL(sURL); g`~;"%u7cn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2wa'WEx
httpConnection.setRequestProperty("User-Agent","NetFox"); Io tc>!
String sProperty = "bytes="+nStartPos+"-"; >qUD_U3A
httpConnection.setRequestProperty("RANGE",sProperty); 1tTY)Evf
Utility.log(sProperty); kh8 M=
ff=RKKnN
k5*Z@a
InputStream input = httpConnection.getInputStream(); x3F94+<n{
//logResponseHead(httpConnection); 7%G&=8tq
u$X =2u:P
I}m>t}QRI_
byte[] b = new byte[1024]; u68ic1
int nRead; c~}FYO$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BqM[{Kv
{ nU0##
nStartPos += fileAccessI.write(b,0,nRead); @H^\PH?pp
//if(nThreadID == 1) 7K+eI!m.s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m>?|*a,
} Kjpsz];
lTVz'ys
g4{0
Utility.log("Thread " + nThreadID + " is over!"); F~~9/#
bDownOver = true; F%4N/e'L
//nPos = fileAccessI.write (b,0,nRead); %Aa_Bumf*:
} )6eFYt%c
catch(Exception e){e.printStackTrace ();} K92M9=>
} }:[MSUm5
} =h|7bYLy
RRzLQ7J
n57mh5mixM
//打印回应的头信息 rrq7UJ;
public void logResponseHead(HttpURLConnection con) eLbh1L
{ a&dP@)
for(int i=1;;i++) r{_1M>F D!
{ >GzH_]
String header=con.getHeaderFieldKey(i); 7[i&EPN
if(header!=null) qD/h/
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r"p"UW9og
Utility.log(header+" : "+con.getHeaderField(header)); o{ccO29H/
else :9(w~bB9$
break; L(X}37
} lQ"t#b+
} P ?96;
7HL23Vrk
O2fFh_\
public void splitterStop() *Wcq'S
{ aC<fzUD;
bStop = true; 5HTY ~&C
} F=f9##Y?7M
)i\foSbB`V
SRU#Y8Xv|
} 1v<uA9A%[
W .Al\!Gi
V8b^{}nxt
/* =$ubSfx
**FileAccess.java NxB/U_j
*//文件访问(定位，写) ;=@?( n
package NetFox; }.=@^-JBA5
import java.io.*; AJ6O>Euq
l1%*LyD
@V@<j)3P
public class FileAccessI implements Serializable{ 9WHarv2@
]eX(K5 A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 rP/W,! 7:K
RandomAccessFile oSavedFile; &ha<pj~
long nPos; T(k:\z/
L Z3=K`gj
>feeVk
public FileAccessI() throws IOException JD AX^]
{ KqNsCT+j
this("",0); f917F.1I
} k9c`[M
Z'm( M[2K
|>-0q~
public FileAccessI(String sName,long nPos) throws IOException zOJzQZ~
{ Yi19VU|/
oSavedFile = new RandomAccessFile(sName,"rw"); GB>T3l"
this.nPos = nPos; akwS;|SZ
oSavedFile.seek(nPos); h(^[WSa
} maV*+!\
"c![s%
9Z3Vf[n5\
public synchronized int write(byte[] b,int nStart,int nLen) eO{2rV45O
{ WckWX]};S
int n = -1; pwF])uf*{\
try{ zCu+Oi6
oSavedFile.write(b,nStart,nLen); eEeK ]8@
n = nLen; gV'=uz v
} 7'@~TM
catch(IOException e) wB<cW>6
{ {P%\& \{F
e.printStackTrace (); ("=24R=a
} Cio(Ptt:
Yof]
AZ-JaE
return n; "<"s&ws;k
} 4X0ku]
b'RBel;W
0iz\<' p
} !T}R=;)eh
*4l6+#W
"2T* w~V&y
/* 0 Gq<APtr
**SiteInfoBean.java &*~_ "WyU
*/ ^n\g,
package NetFox; #Q|ACNpYM
1NK,:m
3:b5#c?R-
public class SiteInfoBean { 4c.!^EiV
0X%#9s~
U{HBmSR
private String sSiteURL; //Site's URL |Lc.XxBkc
private String sFilePath; //Saved File's Path 5g2:o^
private String sFileName; //Saved File's Name }w)wW1&
private int nSplitter; //Count of Splited Downloading File F5\{`
^YEMR C
*bi;mQ
public SiteInfoBean() (T",6xBSG
{//nSplitter的缺省值为5 ZrWA,~;
//default value of nSplitter is 5 0EC/l OS
this("","","",5); Vj[,o Vt$
} i\{fM}~W$
SqoO"(1x
eW[](lGWM
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) )N&95\u
{ w X.]O!^X~
sSiteURL= sURL; `V?NS,@$
sFilePath = sPath; ")W5`9
sFileName = sName; y"ms;w'z
this.nSplitter = nSpiltter; ?C_Y2JY
]yas]5H
DWU(ld:_
} yuF\YOA9
kX:8sbZ##4
7#9fcfL
public String getSSiteURL() ;GZ'Rb
{ @DyMq3Gt?&
return sSiteURL; g<i>252>
} [ _&z+
2c5)pIVEy
8ZDWaq8^2N
public void setSSiteURL(String value) !:1BuiL
{ |PLWF[+t8
sSiteURL = value; "T6s;'k
} p%e/>N.P
a,[NcdG
N\x<'P4q
public String getSFilePath() P)UpUMt;k
{ l,j0n0h.
return sFilePath; J8DKia|h(
} smuQ1.b
@Sz7*p
,L8(Vo`-
public void setSFilePath(String value) Ewo6Q){X
{ DXfQy6k'
sFilePath = value; (}CA?/
} 3:gF4(.
0y/P
iM{cr&0
public String getSFileName() <;NxmO<%\
{ :Y&h'FGZm
return sFileName; F=$U.K~1?
} .c_qMTm"
Q_|Lv&
|TuFx=~5v
public void setSFileName(String value) .WW|v
{ iMp_1EXe
sFileName = value; 8jgamG
} \-:4TuU
eo4v[V&
R9%"Kxm
public int getNSplitter() M}9PicI?7
{ uq@_DPA7
return nSplitter; HQrx9CXE
} 7]8apei|
(EOYJHZB!
Gv6#LcF#
public void setNSplitter(int nCount) k)S'@>n{u
{ }zHG]k,j
nSplitter = nCount; {OW.^UIq^
} BE," lX
} ef -PlGn
qjLFgsd
Ert` ]s~
/* DgC;1U'
**Utility.java W/<C$T4
*/ 93y!x}
package NetFox; lhJZPnx~
&y:SK)
6>/g`%`N
public class Utility { e}W|wJ):j@
MrpT5|t
76EMS?e
public Utility() >3y:cPTM5
{ }<G#bh6;Q
b$eZ>X
rFYw6&;vOi
} YW^sf,zQ
s;YuB#Z
//线程睡眠 gJuA*^
public static void sleep(int nSecond) T3^(I~03
{ CYN|
try{ ~ ^)4*@i6
Thread.sleep(nSecond); 0uf)6(f
} 0-zIohSJdQ
catch(Exception e) xX{gm'3UYa
{ P}mn2Hs
e.printStackTrace (); +:m'
} ?h'd\.j{
} FFID<Lf/2
?-9It|R
//日志 0o-KjX?kP
public static void log(String sMsg) qX!P:M
{ .06[*S
System.err.println(sMsg); +[$ Q C*
} @ykM98K
I0C$
(Zv/(SE5%
public static void log(int sMsg) l*<RKY8
{ h$q=NTV
System.err.println(sMsg); $qh?$a
} "A,-/~cBV
} F<A[S"
<LA!L
2$gOe^ &
/* eEMU,zCl
**TestMethod.java [f\TnXq24
*/ =9#cf-?
package NetFox; R(N5K4J
t5jZ8&M5]
fkK42*U@r
public class TestMethod { \Dr?}D
".T&nS[z
K,L
public TestMethod() (uskVK>L
{ ///xx/weblogic60b2_win.exe @If ^5s;z
try{ Y+UM>
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); SFx|9$hXm
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); UBvea(z-#
SiteFileFetch fileFetch = new SiteFileFetch(bean); C.oC@P
fileFetch.start(); u.L{3gkT
} uO;_T/^u
catch(Exception e){e.printStackTrace ();} uPveAK}h
q3-V_~5^/z
OMVK\_oXo
} UFY_.N~
7Q3a0`Iq
k874tD
public static void main(String[] args) x6={)tj
{ !`?*zf
new TestMethod(); 6l-V%3-
} Q7@.WG5
} o$+"{3svw?
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