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)); - P"
} YLS*uXB&.
for(int i=0;i<nEndPos.length-1;i++) $My~sN8
{ t*dq*(3"c
nEndPos = nStartPos[i+1]; a7=lZZ?
} !6z{~Z:
nEndPos[nEndPos.length-1] = nFileLength; B@#vS=g
} r'lANl-v
} 0{u%J%;
NjPQT9&3h
AX Q.E$1g
//启动子线程 I*$-[3/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; d+6q%U
for(int i=0;i<nStartPos.length;i++) mIPDF1=)
{ $RunGaX!=N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KD\sU6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), \ H#"
nStartPos,nEndPos,i); TAqX f_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z[B:6\oQ
fileSplitterFetch.start(); tR2%oT>h
} l2YA/9.
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,?HM5c{'[Y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mNEh\4ai
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", O%6D2d
nEndPos = " + nFileLength); u} +?'B)
// fileSplitterFetch[nPos.length-1].start(); FvO,* r9
Oi]B%Uxy=
fVVD}GM=
//等待子线程结束 P,xJVo\
//int count = 0; =BJe}AV
//是否结束while循环 bTZ.y.sI
boolean breakWhile = false; atmW? Z
.:GOKyr(~
#{^qBP[
while(!bStop) !H<%X~|,
{ yy[Y=
write_nPos(); YU!s;h
Utility.sleep(500); BjA$^i|8
breakWhile = true; SXN]${
@1<VvW=
0\s&;@xKk
for(int i=0;i<nStartPos.length;i++) ^,)nuUy
{ bI_MF/r''
if(!fileSplitterFetch.bDownOver) @; I9e
{ #!%zf{(C+
breakWhile = false; Oamz>Hplu
break; <G`1(,g
} }' sW[?ik
} 1L!jI2~x}
if(breakWhile) `e?~c'a@
break; O: #SjjK
r* l c#
lV$#>2Hh5
//count++; ckv8QAm
//if(count>4) $<Y%4LI
// siteStop(); jzZ]+'t
} 8OO[Le]1
U0srwt97S
&\Lu}t7Ru
System.err.println("文件下载结束！"); ZLPj1L
} c@)?V>oe
catch(Exception e){e.printStackTrace ();} &%8IBT
} }$r]\v
N93R(x)%
n}fV$qu
//获得文件长度 TeO'E<@
public long getFileSize() K5\l (BB
{ UO!} 0'
int nFileLength = -1; e$JCak=
try{ zr_L V_e
URL url = new URL(siteInfoBean.getSSiteURL()); &A`,hF8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y(2Z<d
httpConnection.setRequestProperty("User-Agent","NetFox"); Jf\`?g3#
(0.JoeA`y
R*XZPzg%
int responseCode=httpConnection.getResponseCode(); yF%e)6
if(responseCode>=400) Q<ia
{ E*fa&G~s )
processErrorCode(responseCode); Kp1 F"!
return -2; //-2 represent access is error q^n LC6q
} ;Ru[^p.{
Y6v#0pT
\Sv|yQUT
String sHeader; %y*'bS
t)g%9 k^
`PvS+>q
for(int i=1;;i++) XW@C_@*J
{ `D$^SHfyz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o_[~{@RoR
//Utility.log(in.readLine()); 2;3&&yK2b
sHeader=httpConnection.getHeaderFieldKey(i); W- nS{v(
if(sHeader!=null) fwMYEj
{ Ro<x#Uo
if(sHeader.equals("Content-Length")) [McqwU/Q
{ :}/\hz ,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); LP'q$iB!
break; ^N 4Y*NtV7
} g)D@4RM
} [z+YXs!N
else ^tWSu?9
break; wL^x9O|`p9
} ; C(5lD&\5
} i[{*(Y$L
catch(IOException e){e.printStackTrace ();} >;%QW
catch(Exception e){e.printStackTrace ();} lA;^c)
+aPe)U<t
]KXyi;n2
Utility.log(nFileLength); 8>D*U0sNl
]#rV]As
E}a.qM'
return nFileLength; 4^4T#f2=e
} RL/7>YQ
ua &uR7
1/qD5 *`Y
//保存下载信息（文件指针位置） _bg Zl
private void write_nPos() jVN=_Y}\
{ d(R8^v/L
try{ Fm6]mz%~u#
output = new DataOutputStream(new FileOutputStream(tmpFile)); GK6CnSV8d
output.writeInt(nStartPos.length); UX.rzYM&T
for(int i=0;i<nStartPos.length;i++) )1R[X!KQ7
{ Tyb'p9
// output.writeLong(nPos); riaL[4c
output.writeLong(fileSplitterFetch.nStartPos); g}K/ba'
output.writeLong(fileSplitterFetch.nEndPos); $=^}J6
} /h`gQyGuY
output.close(); QMrH%Y
} E?|NYu#I6
catch(IOException e){e.printStackTrace ();} X%fLV(
catch(Exception e){e.printStackTrace ();} !8W0XUqh+
} CRrEs 18;#
IB 4L(n1
>9#) obw
//读取保存的下载信息（文件指针位置） =?wDQ:
private void read_nPos() QR8]d1+GV
{ nGc'xQy0
try{ W$J.B!O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); _FS #~z'j
int nCount = input.readInt(); nU\.`.39 +
nStartPos = new long[nCount]; kApDD[N
nEndPos = new long[nCount]; 8oRq3"
for(int i=0;i<nStartPos.length;i++) Pc5C*{C
{ T?=]&9Y'
nStartPos = input.readLong(); d7zZ~n
nEndPos = input.readLong(); uk,9N
} In!^+j
input.close(); b].U/=Hs
} xXmlHo<D
catch(IOException e){e.printStackTrace ();} eWD!/yr|
catch(Exception e){e.printStackTrace ();} /l3Oi@\
} Gi$\th,
"[7'i<,AI
\VW":+
private void processErrorCode(int nErrorCode) qf<o"B|_9
{ '.S02=/
System.err.println("Error Code : " + nErrorCode); \9od*y
} b'R]DS{8
.W2w/RayC
mL'A$BR`
//停止文件下载 QyZ'%T5J
public void siteStop() XH/!A`ZK
{ ]*U; }
bStop = true; Q`Pe4CrWvu
for(int i=0;i<nStartPos.length;i++) HJpx,NU'
fileSplitterFetch.splitterStop(); (dO0`wfM
V|HO*HiB3
}NdLd!
} |o(te
} DZb0'+jQ
//负责部分文件的抓取 T%Zfo7
**FileSplitterFetch.java 6Rq +=X
*/ e},:QL0X
package NetFox; xt`a":lru
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EUH9R8)
import java.io.*; w Bm4~~_
import java.net.*; s*i,Ph
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public class FileSplitterFetch extends Thread { 4mX]JH`UTe
L5 Ai
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String sURL; //File URL fLSDt(c',
long nStartPos; //File Snippet Start Position d& v 7l
long nEndPos; //File Snippet End Position J<Ki;_=I
int nThreadID; //Thread's ID O(.eHZ=
boolean bDownOver = false; //Downing is over h2:TbQ
boolean bStop = false; //Stop identical Bqk+ne
FileAccessI fileAccessI = null; //File Access interface <+b~E,
!A|}_K1Cr
JPj/+f
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException %.\+j,G7
{ >Kl_948
this.sURL = sURL; aE"dpYQ
this.nStartPos = nStart; =i7CF3
this.nEndPos = nEnd; >Apa^Bp
nThreadID = id; ATmyoN2@>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,5 3`t
} iF.f*3-NJB
uOKdb6]r6
T`<Tj?:^&
public void run() "15frr?
{ 92b}N|u
while(nStartPos < nEndPos && !bStop) "EWq{l_I5$
{ ;9J6)zg !n
61HJ%
uLI;_,/:
try{ JZ-64OT
URL url = new URL(sURL); ?"?AH/ED
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 'C:i5?zh(q
httpConnection.setRequestProperty("User-Agent","NetFox"); Rx.5;2m
String sProperty = "bytes="+nStartPos+"-"; h_\W7xt
httpConnection.setRequestProperty("RANGE",sProperty); Lc-WfzT
Utility.log(sProperty); )RWukr+
UKB/>:R
+9<:z\B|
InputStream input = httpConnection.getInputStream(); 9uX15a
//logResponseHead(httpConnection); ]Al)>
|B^Picu
ke/4l?zs
byte[] b = new byte[1024]; 4)L};B=
int nRead; PBiA/dG[;
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) FS('*w&bP
{ ~ySsv
nStartPos += fileAccessI.write(b,0,nRead); ZR{YpLFQ
//if(nThreadID == 1) Lo}/k}3Sx
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); _Ii=3Qsf
} lC d\nE8G
*$1F|G
X>]<rEh
Utility.log("Thread " + nThreadID + " is over!"); yRQNmR;Uy
bDownOver = true; 2:yXeSeA
//nPos = fileAccessI.write (b,0,nRead); X1V~.kvt)
} hOdU%
catch(Exception e){e.printStackTrace ();} 2G3Hi;q18
} ^R7X!tOq4
} YXdo&'Q<qX
?D_}',Wx
:."+&gb
//打印回应的头信息 gh^w !tH3
public void logResponseHead(HttpURLConnection con) 3 "Qg"\
{ ?TmVLny
for(int i=1;;i++) %?S[{ 4A&
{ tWTC'Gx-J
String header=con.getHeaderFieldKey(i); \3F)M`g
if(header!=null) bIV9cpW
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Mdu\ci)lr
Utility.log(header+" : "+con.getHeaderField(header)); ,.<c|5R
else BcQw-<veu
break; X%7l! k[
} a [f}-t9
} `\=~ $&vjC
~!%G2E!
<si cldz
public void splitterStop() @;S)j!m`
{ q+w] Xs;
bStop = true; 6G_{N.{(
} )M7~RN
<9;X1XtpI
Ngm/5Lc
} z38Pi
s)sT\crP@
[DtMT6F3
/* Z 2$S'}F
**FileAccess.java z 5~X3k7
*//文件访问(定位，写) Pb59RE:7V
package NetFox; 8CvNcO;H0
import java.io.*; m/,8\+
GQE7P()
A43[i@o
public class FileAccessI implements Serializable{ *WWDwY@!u
\vW'\}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 {L M Q
RandomAccessFile oSavedFile; /}5)[9GC
long nPos; Q}g"pl
]^@m $O
PevT`\>
public FileAccessI() throws IOException VZ9`Kbu
{ VQ+G.
this("",0); b,(<74!#8
} v~YGef;D
)2:U]d%pk
6/Z_r0^O
public FileAccessI(String sName,long nPos) throws IOException ,z+n@sUR:
{ V.ae 5@;
oSavedFile = new RandomAccessFile(sName,"rw"); &u(pBr8B
this.nPos = nPos; 91k-os(4]
oSavedFile.seek(nPos); +.*=Fn22
} F C=N}5u
9*r l7
e8z?) 4T
public synchronized int write(byte[] b,int nStart,int nLen) <DEu]-'>
{ $bZ5@)E
int n = -1; *I k/Vu%;
try{ 3i9~'j;F3
oSavedFile.write(b,nStart,nLen); jgfr_"@A
n = nLen; e&Z ?I2J
} A3.pz6iT>
catch(IOException e) 1h{7dLA
{ 5/HkhTyj
e.printStackTrace (); QS-X_
} /In=u6D O
DYgz;Y/%l
>;fn,9w
return n; 4-C'2?
} sAF="uB
F-D$Y?m
RXO5pd
} D\pX@Sx,v[
V7 hO}
t ^1uj:vD
/* +zl[C
**SiteInfoBean.java xb&,9Lxd|
*/ 5BM6Pnle
package NetFox; mdcsL~R
J{nA ?[
)6px5Vwz
public class SiteInfoBean { hE4qs~YB!
\|Y_,fi
5wv7]F<
private String sSiteURL; //Site's URL !'Hd:oD<
private String sFilePath; //Saved File's Path =RofC9,
private String sFileName; //Saved File's Name mRC
private int nSplitter; //Count of Splited Downloading File V2'5doo
yFTN/MFt
]Z*B17//
public SiteInfoBean() <s'0<e!./t
{//nSplitter的缺省值为5 65rf=*kz:
//default value of nSplitter is 5 Mh@n>+IR
this("","","",5); LeNSjxB
} m'uFj !
7{NH;U t
C879eeJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) @r\{iSg&g.
{ q/qig5Ou
sSiteURL= sURL; h)z2#qfc
sFilePath = sPath; #E_<}o
sFileName = sName; #+|0o-
this.nSplitter = nSpiltter; U/h@Q\~U
akWOE}5#
,z>w^_
} 1L=)93,M
8K&=]:(
3XNk*Y[5
public String getSSiteURL() }|Bs|$q
{ :b;`.`@KL_
return sSiteURL; zqp>Xw
} EWOa2^%}Z\
vXG?8Q
Xu|2@?l9
public void setSSiteURL(String value) 0(o.[%Ye
{ h]j>S
sSiteURL = value; ;f} ']2
} !mUO/6Q hq
4AKPS&k;
<@Y`RqV+
public String getSFilePath() eAG)+b
{ vD(:?M
return sFilePath; + 7wMM#z
} p+b$jKWQ
Hk=HO|&<XB
SEH[6W3
public void setSFilePath(String value) goJ'z|))
{ g~76c.u-
sFilePath = value; j@{dsS:6
} .-Dc%ap]
al7D3J
$ k_6
public String getSFileName() @\W-=YKLg
{ NnaO!QW%
return sFileName; K@a#^lmd
} xT!<x({
QuC_sFP10
[ B*r{
public void setSFileName(String value) f85~[3 J
{ )g KC}_h=
sFileName = value; )RQQhB
} pX1Us+%
)c532 y
J5Ti@(G5V
public int getNSplitter() zU_dk'&,
{ %OP|%^2
return nSplitter; Fqh./@o
} (B!DBnq
<-,y0Y'
#L57d
public void setNSplitter(int nCount) &2I8!Ia
{ F@zTz54t
nSplitter = nCount; Oz)/KZ
} 6;;2e> e
} :39arq
MZ~N}y
w(K|0|t
/* 4vCUVo r
**Utility.java .}:*tvot
*/ 4t>"-/
package NetFox; k$pND,Ws
Tr;.O?@{t}
wc&D[M]-/
public class Utility { 7NnXt'
z#GSt ZT
;<"V}, C
public Utility() e>bARK<
{ ~ H/ZiBL@
p"j&s
(!YJ:,!so
} $aN%[
aIh} j,
//线程睡眠 *B9xL[}
public static void sleep(int nSecond) GK[9IF#_>
{ nq~fH(QY
try{ ixE w!t
Thread.sleep(nSecond); 5u3KL A
} ?Mn~XN4F_
catch(Exception e) {dn:1IcN
{ l}&2A*c.
e.printStackTrace (); M0OIcMTv
} k4E9=y?
} JAT%s %UC
@AK&R~<
//日志 @]p{%"$
public static void log(String sMsg) =K}T; c
{ PZlPC#E-
System.err.println(sMsg); bm4Bq>*=U
} kE|x'(x
T8Q_JQ
Hi*|f!,H?
public static void log(int sMsg) };<?W){!H
{ gQJLqs"F
System.err.println(sMsg); bbDm6,
} iyXd"O
} &xGpbJG
:{B']~Xf
w0vsdM;G
/* uZ'Z-!=CL
**TestMethod.java 5(E&jKn&
*/ 4jZB%tH
package NetFox; 4^ U%` 1
F^S]7{
69apTx
public class TestMethod { ck3+A/ !z
fNfa.0s
AjoIL
public TestMethod() oN%zpz;OR
{ ///xx/weblogic60b2_win.exe %d%?\jVb
try{ ?mSZQF:d@
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *ZFF$0}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J9DI(`
SiteFileFetch fileFetch = new SiteFileFetch(bean); H)EL0 Kv/
fileFetch.start(); GIn%yB'
} {2q0Ko<
catch(Exception e){e.printStackTrace ();} R.Fl5B
+ #E?)
pU'>!<zGr
} kqxq'Aq)d
@^ *62
X%kJ3{
public static void main(String[] args) 7YK6e
{ >]C/ Q6
new TestMethod(); mg@Ol"2
} (@qS
} AE~@F4MK
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