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)); l49*<nkmq
} <<+\X:,
for(int i=0;i<nEndPos.length-1;i++) <}<zgOT[1!
{ Fcd3H$Na;
nEndPos = nStartPos[i+1]; `*_mP<Ag
} 6{n!Cb[e
nEndPos[nEndPos.length-1] = nFileLength; !g5xq
} 5=v}W:^v.
} ow_W%I=6
9Iwe2lu
"Zl5<
//启动子线程 JBE!j-F
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; x:),P-~w
for(int i=0;i<nStartPos.length;i++) }<@b=_>S
{ S- pV_Ff
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :.Jf0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x[h^[oF0
nStartPos,nEndPos,i); gkES5Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \m(VdE
fileSplitterFetch.start(); Cd,jDPrw
} X*/ho
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gtk7)Uh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); D^l%{IG
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", g!lWu[d
nEndPos = " + nFileLength); Cs9.&Y
// fileSplitterFetch[nPos.length-1].start(); bM{s T"
x3 q]I8q
uE%r/:!k4$
//等待子线程结束 95 ;x=ju
//int count = 0; M+U9R@
//是否结束while循环 yeXx',]a
boolean breakWhile = false; w80oXXs[#
nuk*.Su
'*5i)^
while(!bStop) -I8=T]_D
{ tnH2sHby
write_nPos(); "P7nNa
Utility.sleep(500); {1UQ/_
breakWhile = true; Yw^m
Fq|Ni$
9^oKtkoDZ
for(int i=0;i<nStartPos.length;i++) TW)c#P43K
{ w_.F' E
if(!fileSplitterFetch.bDownOver) .E`\MtA
{ ~Sj9GxTe
breakWhile = false; % tS,}ze
break; K#6P}tf
} /N=b\-]
} &e @2
if(breakWhile) B2>H_dmQ
break; 'u*DA|HC
`[f*Zv w
>V-A;S:
//count++; zk$FkbX
//if(count>4) \k.{-nh
// siteStop(); pMw*9sX
} [tlI!~Z
\pPY37l
>0/i[k-dk
System.err.println("文件下载结束！"); ur)9x^y
} z* ^_)Z
catch(Exception e){e.printStackTrace ();} 8IlunJ
} s'!Cp=xQF"
=bfJ^]R
((H^2KJn
//获得文件长度 zZL6z4g
public long getFileSize() wxKX{Bs
{ pmuvg6@h
int nFileLength = -1; xN5)
try{ *=8JIs A>!
URL url = new URL(siteInfoBean.getSSiteURL()); mWoAO@}Y
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); /)YNs7gR
httpConnection.setRequestProperty("User-Agent","NetFox"); %KsEB*'"
MI/MhkS ?
|,S+@"0#
int responseCode=httpConnection.getResponseCode(); 7?#J~.d5
if(responseCode>=400) e|)hG8FlF
{ `F-/QX[:
processErrorCode(responseCode); kjIAep0rT
return -2; //-2 represent access is error uZNTHD
} h}[-'>{
]OM"ZG/^
3x`|
String sHeader; *:Y%HAy*
l{5IUuUi
^]H5h]U'
for(int i=1;;i++) ). <-X^@
{ ^X=arTE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F0GxH?
//Utility.log(in.readLine()); p*< 0"0
sHeader=httpConnection.getHeaderFieldKey(i); N(;1o.~
if(sHeader!=null) '=39+*6?
{ C6VLy x
if(sHeader.equals("Content-Length")) F}F&T
{ ~5NXd)2+Ks
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $mu^G t
break; IbT=8l,Li
} FtpK)9/4
} h?AS{`.1
else '.on)Zd.
break; U_Vs.M.p
} MX$0Op
} ZT'`hK_up
catch(IOException e){e.printStackTrace ();} o*b] p-
catch(Exception e){e.printStackTrace ();} O8+7g+J=!
6"wlg!k8
(uXL^oja
Utility.log(nFileLength); <NR#Y%}-V
r)lEofX,g+
? E1<!~
return nFileLength; :y+2*lV
} r A`V}>Xj
8*W#DH!
XeW<B0~
//保存下载信息（文件指针位置） xqeyD*s
private void write_nPos() VQ(jpns5
{ :G [|CPm-
try{ /$ w%Q-p
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^&B@Uw5{
output.writeInt(nStartPos.length); ojafy}
for(int i=0;i<nStartPos.length;i++) Ghu#XJB?
{ -?H#LUk
// output.writeLong(nPos); 2V"B:X\
output.writeLong(fileSplitterFetch.nStartPos); Q!o'}nA
output.writeLong(fileSplitterFetch.nEndPos); jfP*"uUK
} zpzK>DH(
output.close(); o\[~.";Z
} aAZZ8V
catch(IOException e){e.printStackTrace ();} cm&nd'A't
catch(Exception e){e.printStackTrace ();} N,`$M.|?
} SbND Y{5RO
?}Z1bH
Z 6t56"u
//读取保存的下载信息（文件指针位置） $3W;=Id=+
private void read_nPos() <5-[{Q/2z
{ O_2pIbh
try{ z#zI1Am(O
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); bZ?v-fn\D,
int nCount = input.readInt(); 9/{(%XwX
nStartPos = new long[nCount]; SAH-p*.
nEndPos = new long[nCount]; -j+UMlkB
for(int i=0;i<nStartPos.length;i++) dV*]f$wQ
{ &#o~U$GBg
nStartPos = input.readLong(); O%Scjm-^X
nEndPos = input.readLong(); 'OE&/ C[
} =qoWCmg"&
input.close(); 8{|8G-Mi
} [8P:?nDDL
catch(IOException e){e.printStackTrace ();} hP=WFD&
catch(Exception e){e.printStackTrace ();} I.WvLLK2
} 3YeG$^y"
fWCo;4<5?
S$f9m
private void processErrorCode(int nErrorCode) 5<iV2Hx
{ q VjdOY:z
System.err.println("Error Code : " + nErrorCode); wa(8Hl|Y
} Qn^'
Km%]1X7T6
A|CmlAW~^
//停止文件下载 &LmJ!^#
public void siteStop() s6ZuM/Q
{ tf=6\p
bStop = true; KLU-DCb%
for(int i=0;i<nStartPos.length;i++) :lX!\(E2
fileSplitterFetch.splitterStop(); ~9?cn
}elc `jj
@v$Y7mw3D
} \@-@Y
} xqXo0
//负责部分文件的抓取 t#yk->,
**FileSplitterFetch.java (ScxLf=]
*/ n+! AnKq
package NetFox; 5(Cl1Yse=r
]fm'ZY&
S_iMVHe
import java.io.*; 2{M^,=^>
import java.net.*; &w4?)#
Hh%I0#
Okgv!Nt8)A
public class FileSplitterFetch extends Thread { cO-7ke
l+3[ KCE
zuP B6W^
String sURL; //File URL ,c$,!.r
long nStartPos; //File Snippet Start Position F^l[GdUosK
long nEndPos; //File Snippet End Position B*qi_{Gp
int nThreadID; //Thread's ID pb^i^tA+A
boolean bDownOver = false; //Downing is over 2^XGGB0
boolean bStop = false; //Stop identical SEORSS
FileAccessI fileAccessI = null; //File Access interface h}-3\8 >
Pl(Q,e7O]
@<<<C?CTv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException cD@(/$wt
{ w;D+y*2
this.sURL = sURL; J%8(kWQ|
this.nStartPos = nStart; "-y-iJ
this.nEndPos = nEnd; Ulhk$CPA
nThreadID = id; w^(<N7B3T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 H!vax)%-\
} agkA}O
yH7F''O7
(VS5V31"
public void run() kTKq/G,Ft
{ sPd Gw~{
while(nStartPos < nEndPos && !bStop) kSC}aN'
{ >82@Q^O
%el"BSB
/{|EAd{
try{ UsgK
URL url = new URL(sURL); <Q$@r?Mu]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wU8Mt#D!
httpConnection.setRequestProperty("User-Agent","NetFox"); <wZQc
String sProperty = "bytes="+nStartPos+"-"; 2*rH?dz8E
httpConnection.setRequestProperty("RANGE",sProperty); g"Ljm7
Utility.log(sProperty); jNe`;o
"rTQG6`
@HT% n
InputStream input = httpConnection.getInputStream(); aGK?x1_
//logResponseHead(httpConnection); SH3|sXH<
!GOM5z,
e}mD]O}
byte[] b = new byte[1024]; hp8%.V$f
int nRead; rL/H2[d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r/& sub"X
{ v. %R}Pa
nStartPos += fileAccessI.write(b,0,nRead); FE" y\2}
//if(nThreadID == 1) $m7?3/YG
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )64@2~4y
} ,PlO8;5]
4!$s}V=6
p/(~IC"!J
Utility.log("Thread " + nThreadID + " is over!"); H&F9J^rC
bDownOver = true; El<]b7
//nPos = fileAccessI.write (b,0,nRead); V7#Ffi
} >tTj[cMJl
catch(Exception e){e.printStackTrace ();} nYWvTvZ
} 0ph{
} P-`M
ur*T%b9&
m7&O9?X
//打印回应的头信息 -yR.<KnL
public void logResponseHead(HttpURLConnection con) C(S'#cm
{ OF%B[h&
for(int i=1;;i++) wg ^sGKN
{ &P.4(1sC
String header=con.getHeaderFieldKey(i); "dsU>3u
if(header!=null) s?zAP O8Sz
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ktK_e
Utility.log(header+" : "+con.getHeaderField(header)); (&&4J{`W9
else *o-.6OxZ$
break; :*t"8;O[
} nM\eDNK
} QF-LU
1?)Xp|O
i.=w]S j
public void splitterStop() lAzjN~V
{ iQ4);du
bStop = true; YWMGB#=
} 76>7=#m0u'
1J6,]M
xO1[>W
} J~B<7O<?!1
U`,0]"Qk
$p#%G#T
/* 76V 6cI=+
**FileAccess.java Vm5c+;
*//文件访问(定位，写) ]BtbWKJBqe
package NetFox; *4U^0e
import java.io.*; YhbZ'SJ
[~kdPk
wUiys/OVM
public class FileAccessI implements Serializable{ ET_W-
WJNl5^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 +zrAG24q
RandomAccessFile oSavedFile; XQ%?
long nPos; n8uv#DsdK
SF}<{x_
7@Zx@
public FileAccessI() throws IOException {g2@6ct
{ &=<x#h-
this("",0); \\{J'j>{f
} S{FROC~1R
WuPH'4b 5
:@1eph0
public FileAccessI(String sName,long nPos) throws IOException %)[+%57{
{ [01.\eh
oSavedFile = new RandomAccessFile(sName,"rw"); y;t6sM@
this.nPos = nPos; *.~6S3}
oSavedFile.seek(nPos); BYO"u6
} UbEb&9}
bV edFm
=8r 0 (c
public synchronized int write(byte[] b,int nStart,int nLen) &FH2fMLQ
{ )x}l3\s
int n = -1; }Ow>dV?
try{ e{X6i^% m_
oSavedFile.write(b,nStart,nLen); 56e r`=ms
n = nLen; gzjR6uz
} ME;n^y\8
catch(IOException e) VR+<v
{ Z|_K6v/c
e.printStackTrace (); qOSg!aft{Q
} @g2cC
>$ NDv
/n5F(5<
return n; %VzKqh
} \A#1y\ok
nSF``pp+
{%VV\qaC
} hq:&wN7Q
ZunCKc
/;7y{(o
/* e1>aTu@
**SiteInfoBean.java }j2Y5
*/ (RUT{)p[
package NetFox; ~by]xE1Eg
N[<H7_/3
7]x3!AlV
public class SiteInfoBean { i `s|,"0o
"S&@F/
HQUeWCN
private String sSiteURL; //Site's URL 2:BF[c`
private String sFilePath; //Saved File's Path %/c+`Wd/l$
private String sFileName; //Saved File's Name K,6b3kk
private int nSplitter; //Count of Splited Downloading File :9R=]#uD
:}h>by=
>_c5r?]SG
public SiteInfoBean() "]m+z)lWd
{//nSplitter的缺省值为5 -pU|hSW*b
//default value of nSplitter is 5 ) c/% NiN
this("","","",5); !IC-)C,q
} SG?Nsp^%`B
1VF
5aBAr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Tx1vL
{ -*~CV:2iq-
sSiteURL= sURL; mCs#.%dU
sFilePath = sPath; V~T@6S
sFileName = sName; WpS1a440
this.nSplitter = nSpiltter; 4EXB;[]
n4R2^gXAw
b1gaj"]
} zP:cE
L>!8YUz7p$
uk9g<<3T
public String getSSiteURL() }m/RZP~=
{ ^9_UUzf\
return sSiteURL; jYVE8Y)my
} j7MO'RX`&
'`|AI:L
)jCo%P/
public void setSSiteURL(String value) D?~8za`5
{ [k[u*5hP|F
sSiteURL = value; mv atUe
} hKNY+S})g
rZojY}dWJ
R#n%cXc|
public String getSFilePath() 'q>2t}KG
{ ExSO|g]%
return sFilePath; v!42DA)
} (f_g7B2&y
1[E#vdbT
!Y<oN~<%)
public void setSFilePath(String value) YB)3X[R+0
{ ERdL^T>
sFilePath = value; e,k2vp!<&
} c=[q(|+O!
K9[e>
6*nAo8gl
public String getSFileName() -h-oMqgu(
{ G){g
return sFileName; <w>/^|]#
} 8L5!T6+D&
B/J&l
:%JC^dV(
public void setSFileName(String value) K'1~^)*
{ ]~>K\i
sFileName = value; m,>
} h(B,d,q"
.>Z,uT^A
B|%tE{F
public int getNSplitter() VW@ x=m
{ ukuo:P<a
return nSplitter; |xr\H8:(!
} 6QZ5|T ]
(QB+%2v
J$9:jE-4
public void setNSplitter(int nCount) h?UVDzI!O
{ b8BD8~;
nSplitter = nCount; i3mAfDF
} ]lS@}W\
} cPn+<M#
6+dn*_[Z6
8[bkHfI
/* t~M $%)h
**Utility.java (LJ@SeM;
*/ 68R1AqU_
package NetFox; MR'o{?{e`
XD-^w_
X6RQqen3:
public class Utility { uXQ >WI@eF
]M,06P>?
?mRE'#
public Utility() Bmo$5$
{ F9XT lA
r;iV$Rq!
:a3LS|W
} ?M6ag_h3
$T }Tz7(
//线程睡眠 S{p}ux[}=
public static void sleep(int nSecond) noNm^hFL
{ AxCI 0
try{ xi'<y
Thread.sleep(nSecond); %*)2s,8
} Xt,X_o2m|]
catch(Exception e) FA>1x*;c
{ =qoRS0Qa
e.printStackTrace (); S7n"3.k
} 8*!|8 BPj^
} =^h~!ovj:
o;`!kIQ
//日志 0jB X5
public static void log(String sMsg) gs`^~iD]m
{ V`fL%du,3
System.err.println(sMsg); `1p 8C%
} O|v (58A
IlLn4Iw
<9@7,2
public static void log(int sMsg) M?o{STt
{ 6E9N(kFYs
System.err.println(sMsg); Ly(P=M>"y
} BSXdvI1y
} V2kWiyN
73DlRt *
M%=P)cC
/* g0#q"v55
**TestMethod.java 6w#nkF
*/ x3p9GAd#
package NetFox; vC9@,[
(:$9%,x
aIGn9:\
public class TestMethod { %"7WXOv&z
=B5E0x
5RA<Z.
public TestMethod() (iDBhC;/B
{ ///xx/weblogic60b2_win.exe sQk|I x
try{ e)pTC97^L
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Uu2N9.5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mC(u2
SiteFileFetch fileFetch = new SiteFileFetch(bean); :|XCnK0
fileFetch.start(); fykI,!
} 8[\79|
catch(Exception e){e.printStackTrace ();} #)i&DJ^Y
'yT`ef
%F$N#YG
} MTB@CP!u
>_#)3K1y8
+rQg7a}
public static void main(String[] args) ec?1c&E
{ }|He?[TR
new TestMethod(); 9H$g?';
} a"qR J-@
} *98Ti|
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