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)); jar?"o
} p4b6TI9;
for(int i=0;i<nEndPos.length-1;i++) :4COPUBpPV
{ J=n^&y
nEndPos = nStartPos[i+1]; sn@)L~$V
} g|!=@9[dv
nEndPos[nEndPos.length-1] = nFileLength; Ww{-(Ktx
} -r0oO~KT
} 1;>RK
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//启动子线程 a<V Mh79*
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 52.hJNq#L
for(int i=0;i<nStartPos.length;i++) Yt4v}{+
{ v\kd78,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Io_7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Z \-
nStartPos,nEndPos,i); _g"su#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b|`
fileSplitterFetch.start(); OQT i$2
} (fO~nN{F
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $>%zNq-F
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6(HJYa
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "M]`>eixL
nEndPos = " + nFileLength); qv/chD`C
// fileSplitterFetch[nPos.length-1].start(); x/92],.Mz
9AQ2FD
#-d-zV*
//等待子线程结束 %5(v'/dQ
//int count = 0; G&7 } m
//是否结束while循环 uQW d1>
boolean breakWhile = false; `"bp-/
a&R,jq
1+Y; "tT
while(!bStop) .fY$$aD$4
{ Gv\fF;,R
write_nPos(); nON"+c*
Utility.sleep(500); lt}U,p,S
breakWhile = true; ra\|c>[%
I,lzyxRP
@;d7#!:cE
for(int i=0;i<nStartPos.length;i++) NMP*q @
{ Q9t.*+
if(!fileSplitterFetch.bDownOver) "S&1J8D|
{ }HZ'i;~r|9
breakWhile = false; nSU7,K`PM
break; W@FGU
} c<qJs-C4;
} ^#2Y4[@
if(breakWhile) *km- pp
break; N{zou?+
niM(0p
t]pJt
//count++; :SpPT
//if(count>4) !myF_cv}'
// siteStop(); >Q^*h}IdW
} ;V1e>?3
sk`RaDq@;
lnntb3q
System.err.println("文件下载结束！"); %] 7.E
} <4Cy U j
catch(Exception e){e.printStackTrace ();} Bk~M^AK@~
} (fWQ?6[
\[x4
:~9F/Jx
//获得文件长度 w9a6F
public long getFileSize() MT@Uu
{ SkA"MhX
int nFileLength = -1; 93#wU})
try{ &Lgi
URL url = new URL(siteInfoBean.getSSiteURL()); %|3UWN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); #Y<b'7yJ
httpConnection.setRequestProperty("User-Agent","NetFox"); b~FmX
aD3Q-a[
5($ '@u
int responseCode=httpConnection.getResponseCode(); pG:)u cj
if(responseCode>=400) u@zBE? g
{ -^7n+ QX
processErrorCode(responseCode); zL3'',Ha
return -2; //-2 represent access is error doaqHri\,
} tt>=Vt'
h9J
_26F[R1><~
String sHeader; ktKT=(F&
hC=="4 -
qT L@N9
for(int i=1;;i++) GQ9g$&T
{ D<cHa |
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V]9?9-r
//Utility.log(in.readLine()); 3bPvL/\Lb
sHeader=httpConnection.getHeaderFieldKey(i); 'H,l\i@"
if(sHeader!=null) K<+h/Ok
{ I*K~GXWs#
if(sHeader.equals("Content-Length")) DavG=kvd
{ th*E"@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^UK6q2[
break; x_5H_! \#
} ];go?.*C
} !P0Oq)q
else ?wx|n_3<:
break; 1cdM^k
} bdCpGG9
} etH%E aF[
catch(IOException e){e.printStackTrace ();} dGzZ_Vf
catch(Exception e){e.printStackTrace ();} *l^%7Wrk
4<&`\<jZ
qcfLA~y
Utility.log(nFileLength); _#+~#U%5n
up7]Yy;o=
L1k_AC1.M
return nFileLength; <&rvv4*H
} YvK8;<k@-?
?79ABm a
Tce2]"^;
//保存下载信息（文件指针位置） `D%bZ%25c
private void write_nPos() uIvE~<
{ U{o0Posg
try{ cf0Dq~G
output = new DataOutputStream(new FileOutputStream(tmpFile)); HIi5kv]}|
output.writeInt(nStartPos.length); O=St}B\!m
for(int i=0;i<nStartPos.length;i++) MLcc
{ 3l 0>
// output.writeLong(nPos); m>6,{g)
output.writeLong(fileSplitterFetch.nStartPos); pemb2HQ'4j
output.writeLong(fileSplitterFetch.nEndPos); S0Y$$r
} nV%1/e"5
output.close(); BS;_l"?
} e? fFh,a
catch(IOException e){e.printStackTrace ();} ~V"D|U;i +
catch(Exception e){e.printStackTrace ();} pRj1b^F5y
} D[)g-_3f6<
#^v|u3^DD
GRb"jF>ut
//读取保存的下载信息（文件指针位置） *eytr#0B-
private void read_nPos() [x5T7=
{ >LwZ"IEV
try{ NQ!jkojD
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); q8.K-"f(Q
int nCount = input.readInt(); MDS;qZx=
nStartPos = new long[nCount]; 0>m-J
nEndPos = new long[nCount]; Jx@3zl
for(int i=0;i<nStartPos.length;i++) .4~n|d>z
{ \0m[Ch}~ey
nStartPos = input.readLong(); RI"A'/56
nEndPos = input.readLong(); W9?Vh{w
} W^q;=D6uh
input.close(); |[?"$g9v
} +I7n6s\
catch(IOException e){e.printStackTrace ();} &/4W1=>(
catch(Exception e){e.printStackTrace ();} 'k#^Z
} wEo/H
%uyRpG3,
n9Z|69W6>
private void processErrorCode(int nErrorCode) ^e>`ob
{ ]v3 9ag_hu
System.err.println("Error Code : " + nErrorCode); vO"Sy{)Z>
} Z| Z447_
RUmJ=i'4/
ZUb6d*B
//停止文件下载 \&J7>vu^y
public void siteStop() hd.^ZD7
{ v3Y/D1jd"
bStop = true; *.AokY)_a
for(int i=0;i<nStartPos.length;i++) <5A(rDij
fileSplitterFetch.splitterStop(); B8:_yAv o
&'UYV>
aO?(ZL
} SqTO~zGC
} :grJ}i-D
//负责部分文件的抓取 Ex~[Hk4ow
**FileSplitterFetch.java d$/BF&n
*/ e;56}w
package NetFox; h84}lxT^]
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C$xU!9K[+
import java.io.*; M& GA:`
import java.net.*; cTFyF)
r"SuE:D
yK<%AV@v
public class FileSplitterFetch extends Thread { utC]GiR
JB a:))lw
h&||Ql1
String sURL; //File URL _mKO4Atw
long nStartPos; //File Snippet Start Position S,EXc^A7
long nEndPos; //File Snippet End Position it!8+hvq9*
int nThreadID; //Thread's ID 16[>af0<g
boolean bDownOver = false; //Downing is over _H|x6X1-
boolean bStop = false; //Stop identical |<P]yn
FileAccessI fileAccessI = null; //File Access interface `AeId/A4n
0x'>}5`5
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q-3%.<LL
{ LZV
this.sURL = sURL; xjiMM>|n
this.nStartPos = nStart; [>Kkj;*
this.nEndPos = nEnd; W~ XJ']e
nThreadID = id; [nxjPx9-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 SEF/D0
} W\o(f W
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public void run() _) 2fXG!
{ l=[<gPE
while(nStartPos < nEndPos && !bStop) _=XzQZT!L
{ h*{{_3,
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try{ a-,!K
URL url = new URL(sURL); !-%i" a
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); bN@V=C3
httpConnection.setRequestProperty("User-Agent","NetFox"); ZkkXITQkPM
String sProperty = "bytes="+nStartPos+"-"; @kn0f`
httpConnection.setRequestProperty("RANGE",sProperty); 5zX;/n~
Utility.log(sProperty); /i$E|[
&aldnJ
/pZLt)=P
InputStream input = httpConnection.getInputStream(); Xz&Hfs"/J
//logResponseHead(httpConnection); kehv85
<7/_Vs)F0
c%r?tKG6
byte[] b = new byte[1024]; }kdYR#{s
int nRead; V}=9S@$o
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +.&#whEw(i
{ 8E"Ik~
nStartPos += fileAccessI.write(b,0,nRead); UMuqdLaT9
//if(nThreadID == 1) Gvw4ot/
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ~mx me6"v
} 7OG=LF*V-
M2_sxibI
jzSh|a9_
Utility.log("Thread " + nThreadID + " is over!"); P Ig)h-w?
bDownOver = true; <ZxxlJS)6
//nPos = fileAccessI.write (b,0,nRead); $R%xeih1fz
} pHEhB9_A!
catch(Exception e){e.printStackTrace ();} *fso6j#%
} |\%[e@u
} kMAQHpDD
rY_)N^B|nF
O E0w/{
//打印回应的头信息 T>e!DOW;
public void logResponseHead(HttpURLConnection con) =0TnH<`
{ mS5'q q;t
for(int i=1;;i++) '+N!3r{G
{ e)LRD&Q
String header=con.getHeaderFieldKey(i); uA7~`78
if(header!=null) %+YLe-\?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); \RyOexNZ
Utility.log(header+" : "+con.getHeaderField(header)); FA<|V!a
else R<@s]xX_
break; N|Xx#/
} k{(R.gLZG
} I4:4)V?
{v+,U}
'Ar+k\.J
public void splitterStop() ^&buX_nlO
{ ,y>,?6:>
bStop = true; I3]-$
} G < Z)y#
bO>q`%&
trcG^uV
} Q{T6t;eH
z$$ E7i
>Lx,<sE
/* q 9lz
**FileAccess.java KSnU;B6w>
*//文件访问(定位，写) kg?[
package NetFox; R7}=k)U?d@
import java.io.*; e3,TY.,Ay
5drc8_fZ
@H2c77%
public class FileAccessI implements Serializable{ DW&%"$2
CRf!tsj@
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 F]DRT6)
RandomAccessFile oSavedFile; W~(@*H
long nPos; 7Vd"k;:X
Rd@34"O
kIhP 73M
public FileAccessI() throws IOException GOuBNaU{
{ U>?q|(u
this("",0); }kzGuNj
} 9W88_rE'e}
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NC'+-P'y
public FileAccessI(String sName,long nPos) throws IOException 'NHtCs=F
{ nXPl\|pXt
oSavedFile = new RandomAccessFile(sName,"rw"); IV*@}~BJ
this.nPos = nPos; al/Mgo
oSavedFile.seek(nPos); 9o5W\.A7[D
} %Z9&zmO
.'N:]G@!
{\z&`yD@
public synchronized int write(byte[] b,int nStart,int nLen) |C}n]{*|
{ 07 [%RG
int n = -1; "} =RPc%9
try{ 2u9O+]EP
oSavedFile.write(b,nStart,nLen); l?Vm/YXb
n = nLen; I,;@\
} P"d7Af
catch(IOException e) Y|JC+Ee
{ $BHbnsaQ
e.printStackTrace (); 5p!X}u]
} </! `m8\
^f*}]`S
1{D_30sG.
return n; M &`ZF
} eD5:0;X2
,p2BB"^_i
#yz5CWu
} )c|S)iJ7=z
V@krw"vW
XJJdCv^
/* ms9zp?M
**SiteInfoBean.java !_EL{/ko
*/ W,<L/ZKJ
package NetFox; {6H%4n
GP=i6I6C
|m{Q_zAB
public class SiteInfoBean { 8 Z|c!QIU
M]9oSi
I#lvaoeN
private String sSiteURL; //Site's URL b^ wWg
private String sFilePath; //Saved File's Path R-odc,P=
private String sFileName; //Saved File's Name Gt;@.jY&
private int nSplitter; //Count of Splited Downloading File 70pt5O3]
eyq\a'tyB
YbCqZqk
public SiteInfoBean() >!u@>
{//nSplitter的缺省值为5 1K(a=o[Ce
//default value of nSplitter is 5 F>N3GPRl
this("","","",5); &G63ReW7 @
} "s-e)svB
<3?T^/8
Ce&nMgd~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o=/Cje
{ R}~p1=D
sSiteURL= sURL; 9J>b6
sFilePath = sPath; (EZ34,k'S
sFileName = sName; ?naPti1GX
this.nSplitter = nSpiltter; p#-ov-znp
5vxKkk&i4l
Hgu:*iYA
} H<tk/\C
<eWGvIEP[
$xx5+A%,
public String getSSiteURL() 38Rod]\E
{ $7Sbz&)y3
return sSiteURL; si`{>e~`6P
} ;VQFz&Q$u
JiFy.Pf
W40GW
public void setSSiteURL(String value) {8L)Fw
{ 31BN ?q
sSiteURL = value; 00DWXGt20o
} $#Mew:J
"v.]s;g
P<+y%g(({
public String getSFilePath() m3|KIUP
{ %y@iA91K
return sFilePath; -I, _{3.S
} 44s K2
]J=S\
C):RE<X
public void setSFilePath(String value) B_f0-nKP
{ n])-+[F
sFilePath = value; M~&|-Hm
} #3uBq(-Z
>z=_V|^$
re.%$D@
public String getSFileName() s3G\L<~mB
{ = mnjIp
return sFileName; m~K[+P
} HSt|Ua.c/h
kBPFk t2
R=D\VIu,Z
public void setSFileName(String value) 'WqSHb7
{ %}z/_QZ
sFileName = value; xP@VK!sc
} ` eB-C//
1[k~*QS
9JF*xXd>Q
public int getNSplitter() id^U%4J
{ 2>{_O?UN
return nSplitter; \L#BAB6z
} uj.~/W1,!
Lh=~3
WY@x2bBi
public void setNSplitter(int nCount) f;/t7=>d
{ =k4yWC5-
nSplitter = nCount; /Vpd*obMB
} cz_4cMgxu
} lYd#pNN
kndP?#> p1
nG#lrYZw
/* T[$Sbz`
**Utility.java `1%SXP1
*/ v}6YbY Tq
package NetFox; #Id.MLHxA_
1SBc:!2
qa![oMKc
public class Utility { )k&pp^q\
ujcS>XN,1
`92 D]^g
public Utility() ArkFC
{ c%.f|/.k
9X&Xs/B
>/"XX,3
} %EPqJ(T
bw*@0;
//线程睡眠 oH+UuP2a-J
public static void sleep(int nSecond) v9~Hl
{ [5%/{W,~m
try{ (4V1%0
Thread.sleep(nSecond); {d$S~
} dE5DH~ldV
catch(Exception e) MCma3^/1
{ H+zn:j@~L
e.printStackTrace (); \Rn.ug
} AK<ZP?0
} x7e
D} 0>x~
//日志 :C42yQAP
public static void log(String sMsg) Y51XpcXQ
{ PiB)pUYj
System.err.println(sMsg); }\u~He%
} TJY$<:
98C~%+
[Hdk=p
public static void log(int sMsg) K. G#[
{ Y=G *[G#
System.err.println(sMsg); }wR)p
} 4qda!%
} 4x'^?0H@
1elx~5v1.=
y_"GMw
/* )EO/P+&
**TestMethod.java 9\)NFZ3Mz
*/ 8O{]ML
package NetFox; :0T]p"y4
?HIc=
`n-e.{O((
public class TestMethod { u2<:mu[|P
Oe9{`~
0jv9N6IM
public TestMethod() z>j%-3_1
{ ///xx/weblogic60b2_win.exe Y tGH>0}h
try{ G%YD2<V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @6*<Xs =
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); y<F$@
SiteFileFetch fileFetch = new SiteFileFetch(bean); }sy3Mrb
fileFetch.start(); LWbWj ^
} :yT~.AK}>1
catch(Exception e){e.printStackTrace ();} |iM*}Ix-
?vRz}hiy
Z-4A`@p
} (XqeX(s
RqHxKj
w]yLdfi!
public static void main(String[] args) !xo@i XL
{ U7crbj;c)d
new TestMethod(); q){]fp.,@
} 81W})q8
} W&06~dI1!
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