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)); ]^&DEj{
} {{[).o/
for(int i=0;i<nEndPos.length-1;i++) ^QB/{9#
{ |RwD]2H
nEndPos = nStartPos[i+1]; ,u{d@U^)3@
} bu%@1:l
nEndPos[nEndPos.length-1] = nFileLength; o]}b#U8S
} pt(GpbtWK
} zV4%F"-
[t<^WmgtxL
#'^p-Jdm
//启动子线程 Yiu)0\ o
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q9 kKk
for(int i=0;i<nStartPos.length;i++) A`=ESz
{ 27E6S)zv
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p2!x8`IB*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), -deY,%
nStartPos,nEndPos,i); -d%bc?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H<%7aOwO2
fileSplitterFetch.start(); 0[T!}F^%e
} FD#?pVyPn^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), @*q\$Eg}2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?Hf^&yo
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", doP4N6
nEndPos = " + nFileLength); E`iT>+LG<
// fileSplitterFetch[nPos.length-1].start(); EFf<|v
mh.0% 9`9
T6Ue\Sp'
//等待子线程结束 _xAdvr' W
//int count = 0; @p|[7'
//是否结束while循环 KHcfP7
boolean breakWhile = false; ^P:9iu)+]~
`\q4z-<-
j"_V+)SD
while(!bStop) Rr4r[g#
{ vV#Jl) A
write_nPos(); +tdt>)a
Utility.sleep(500); w^p 'D{{
breakWhile = true; 20zIO.&o
B HoZ}1_
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for(int i=0;i<nStartPos.length;i++) QCa$<~c
{ >efYpd#^
if(!fileSplitterFetch.bDownOver) //Hn[wEOh
{ -YA1Uk
breakWhile = false; mmTc.xh
break; f&8&UL>e`
} 5p94b*l
} ilayU
if(breakWhile) 5^GUuFt5m
break; H=Yl @
5$GE3IER8
.4_EaQ;jX
//count++; xlgN}M
//if(count>4) HHWB_QaL
// siteStop(); ;'}1
} 4rwfY<G
@ L%3}
I@+dE V`Lf
System.err.println("文件下载结束！"); /Kwo^Q{
} &UbNp8h
catch(Exception e){e.printStackTrace ();} M`Y~IG}
} WSi Utf|g
_ 97F
l]T|QhiVd
//获得文件长度 sA3 4`ZAa
public long getFileSize() '"~|L>F%G
{ hP`3Ao
int nFileLength = -1; 7I^(vQ
try{ GLnj& Ve
URL url = new URL(siteInfoBean.getSSiteURL()); %OfaBv&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w;}P<K
httpConnection.setRequestProperty("User-Agent","NetFox"); ztgSd8GGE
yew9bn0a=
/]F3t]FlC
int responseCode=httpConnection.getResponseCode(); 3UslVj1u
if(responseCode>=400) 1f~unb\Gg
{ o`M7:8G
processErrorCode(responseCode); i)+@'!6
return -2; //-2 represent access is error D7[ 8*^
} #XQEfa
C[& \Xq
,hT t]w
String sHeader; KNQX\-=
b0PF7PEEQ
QI=",vmau
for(int i=1;;i++) SD8Q_[rY
{ V. =!^0'A
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;[ pyKh
//Utility.log(in.readLine()); &=<x&4H+
sHeader=httpConnection.getHeaderFieldKey(i); (gvaYKvr
if(sHeader!=null) "CT'^d+
{ fg*IHha
if(sHeader.equals("Content-Length")) p r(:99~3
{ tL 3]9qfj
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); K>lA6i7?
break; %^2LTK(P
} ^7Z)/c`"
} jU@qQ@|
else J6n@|L!yO
break; (](:0H
} ,m8l /wG
} xs.>+(@|;
catch(IOException e){e.printStackTrace ();} Br`Xw^S
catch(Exception e){e.printStackTrace ();} &]ts*qCEL
]6GdB3?UVM
&Jk0SUk MP
Utility.log(nFileLength); DNLqipUw
s34{\/'D+
Gi6sl_"q
return nFileLength; h-<('w:A
} S'9T>&<Kn
//3iai
FU;Tv).
//保存下载信息（文件指针位置） wta\C{{
private void write_nPos() ?Z.p.v
{ -3_-n*k!
try{ )0j^Fq5[+
output = new DataOutputStream(new FileOutputStream(tmpFile)); ">v76%>Z7
output.writeInt(nStartPos.length); eL0U5>#
for(int i=0;i<nStartPos.length;i++) #[qmhU{s
{ =n cu#T]
// output.writeLong(nPos); 8l~]}2LAs
output.writeLong(fileSplitterFetch.nStartPos); ltwX-
output.writeLong(fileSplitterFetch.nEndPos); aiF7\^aw$
} brl(7_2
output.close(); r0+lH:G*q
} g`d5OHvOo
catch(IOException e){e.printStackTrace ();} ; "ux{ .
catch(Exception e){e.printStackTrace ();} 0x4Xs
} K``MS
#OqQD6
plh.-"
//读取保存的下载信息（文件指针位置） 3 i Id>
private void read_nPos() Q0#oR[(
{ Rf^$?D&^
try{ |j^^*z@
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (Dlh;Ic r9
int nCount = input.readInt(); $.a<b^.Xi
nStartPos = new long[nCount]; o:.={)rX
nEndPos = new long[nCount]; 5@%$M$E
for(int i=0;i<nStartPos.length;i++) MT[V1I{LV
{ sG=D(n1
nStartPos = input.readLong(); T&oY:1D,g
nEndPos = input.readLong(); 3%bCv_6B
} )M<"YI)g
input.close(); -+Axa[,5=
} 9y{[@KG
catch(IOException e){e.printStackTrace ();} =3]}87
catch(Exception e){e.printStackTrace ();} F=7X,hK
} 6NPCp/
Oz'x5/%G
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private void processErrorCode(int nErrorCode) <1YINkRz
{ :1^ R$0d
System.err.println("Error Code : " + nErrorCode); $A;jl`ng
} UOJx-o!c?
B8F.}M-!
|L}zB,
//停止文件下载 $sTbFY
public void siteStop() ~Z9Eb|B
{ lr'h
bStop = true; !8lG"l|,l
for(int i=0;i<nStartPos.length;i++) cfBq/2I
fileSplitterFetch.splitterStop(); AyKvh
0"ksNnxK
;R|i@[(J
} J3fk3d`2
} = NHuj.
//负责部分文件的抓取 )_k"_VVcC
**FileSplitterFetch.java IppzQ0'=y1
*/ Ls< ";QJc
package NetFox; @<=xfs
Uy2NZ%rnt
4wjy)VD_
import java.io.*; )h6hN"#V5
import java.net.*; gHdNqOy c
UCG8=+t5T
'3TwrY?-
public class FileSplitterFetch extends Thread { Ydm0
6i|5`ZO
x)N$.7'9OJ
String sURL; //File URL )9I>y2WU~
long nStartPos; //File Snippet Start Position Aslh}'$}-
long nEndPos; //File Snippet End Position #5)0~4%l
int nThreadID; //Thread's ID qB6@OS
boolean bDownOver = false; //Downing is over #S)]`YW
boolean bStop = false; //Stop identical sL" h
FileAccessI fileAccessI = null; //File Access interface @ol=gBU
2l]*><q|
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException I,TJV)B
{ ,cZhkXd
this.sURL = sURL; Y)#x(s?t
this.nStartPos = nStart; R % [ZQK
this.nEndPos = nEnd; ~A@T_*0
nThreadID = id; cq lA"Eof
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G&=4@pLY5
} ,)/gy)~#
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x93h{Kf
public void run() Zk,` Iq
{ kt`_n+G
while(nStartPos < nEndPos && !bStop) BIGln`;,f
{ EQ 'L"
)4:K@
qTSyy=
try{ ~tK4C|
URL url = new URL(sURL); Hdvtgss!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); CD]hi,B_J
httpConnection.setRequestProperty("User-Agent","NetFox"); o>WB,i^G
String sProperty = "bytes="+nStartPos+"-"; <Qg).n>;z
httpConnection.setRequestProperty("RANGE",sProperty); 8(-V pU
Utility.log(sProperty); ffoL]u\
er@"4R0
?*DM|hzOi
InputStream input = httpConnection.getInputStream(); F6 mc<n
//logResponseHead(httpConnection); q^!_jMN5
SnIH6k0T_
f>*T0"\c
byte[] b = new byte[1024]; #b~B 0:U
int nRead; -55[3=#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _y>mmE
{ SeuC7!q{
nStartPos += fileAccessI.write(b,0,nRead); +cH,2^&
//if(nThreadID == 1) 5OEo(&
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a8 X}r.
} e"}JHXs
ba5,?FVI~
AWaptw_p*
Utility.log("Thread " + nThreadID + " is over!"); /{1sU}k-
bDownOver = true; yyPQ^{zD
//nPos = fileAccessI.write (b,0,nRead); "PgVvm#w'
} MB7UI8
catch(Exception e){e.printStackTrace ();} F/pq9
} /ILj}g'
} OlU')0Y
->Z9j(JU
1Vf?Rw
//打印回应的头信息 v C23
public void logResponseHead(HttpURLConnection con) HQp\0NC]
{ F}1h
for(int i=1;;i++) 7bV(eV
{ @jL](Mq|]
String header=con.getHeaderFieldKey(i); l7h6R$7; 0
if(header!=null) EdL2t``
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {F!/\2a
Utility.log(header+" : "+con.getHeaderField(header)); S?b^g'5m
else M)x6m|.=
break; 0Q7teXRM
} ( p(/
} yMG(FAyu
z*V 8l*
su$IXI#R-&
public void splitterStop() .7K)'
{ &9Y ^/W
bStop = true; <`$svM
} mpr_AL!ZO~
epicY
}b5omHUE%
} y^!>'cdV
YD3jP}Ym
yj$$k~@
/* "Jahc.I
**FileAccess.java 2LfiaHO
*//文件访问(定位，写) z`"*60b
package NetFox; jgvzp
import java.io.*; SND@#?hiO
@V?T'@W7D
RWg'W,v=!
public class FileAccessI implements Serializable{ Z";&1cK
` 0$i^,}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /0Jf/-}ovn
RandomAccessFile oSavedFile; eA{nwtN
long nPos; >&DC[)28
pV8_i7\
nND; lVQSO
public FileAccessI() throws IOException 9^L{)t>
{ lRk_<A
this("",0); mEm=SpO[$o
} t[e]AU[}
LR "=(
XF&_**0n
public FileAccessI(String sName,long nPos) throws IOException `@q\R-`
{ ^B_SAZ&%%
oSavedFile = new RandomAccessFile(sName,"rw"); PglSQ2P
this.nPos = nPos; <4LW.q
oSavedFile.seek(nPos); F?z:[1(:
} vfd<qdi3p(
/0swrt.
,i jB3J
public synchronized int write(byte[] b,int nStart,int nLen) }qw->+nD
{ A"B#t"
int n = -1; MY60%
try{ eRqPZb"6MR
oSavedFile.write(b,nStart,nLen); J$W4AT
n = nLen; T@Bu Fr`]<
} _Sg"|g
catch(IOException e) gSa!zQN6
{ `h|Y0x
e.printStackTrace (); cP",szcY
} Dm@h'*
Z0/$XS9|h;
|KR8=-!7
return n; lak,lDt]
} ~.tl7wKkR/
\.aKxj5
4tEAi4H|`@
} NXk~o!D
eZoAy[
fikDpR
/* 4]HW!J
**SiteInfoBean.java .L9g*q/}
*/ d5>EvK U
package NetFox; t~H0Qeb[v=
'3w%K+eJY
5hHLC7tT9
public class SiteInfoBean { #bJp)&LO
.=)[S5.BVq
abAw#XQ8
private String sSiteURL; //Site's URL BbM/Rd1tAm
private String sFilePath; //Saved File's Path _!_^B
private String sFileName; //Saved File's Name YQ@2p?4m
private int nSplitter; //Count of Splited Downloading File EKD#s,(V*X
!F:mDZeY
xk
public SiteInfoBean() 3RX9LJGX
{//nSplitter的缺省值为5 0h~{K
//default value of nSplitter is 5 !{4'=+
this("","","",5); )7{r8a
} f|=u{6
QE8`nMf
m2H?VY.^K
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) g[R4/]K^$
{ aNn4j_V(
sSiteURL= sURL; UGlHe7
sFilePath = sPath; 76o3Sge:
sFileName = sName; 7|o!v);uR
this.nSplitter = nSpiltter; )QWhzY
a)4%sX*I
.EPv4[2%F8
} :L{*B$c
b9ud8wLE[
Uqz.Q\A
public String getSSiteURL() QI'-I\Co
{ )@p?4XsT4J
return sSiteURL; .R@s6}C`}=
} aZ|?i }
em95ccs'-
LzJ`@0RrX
public void setSSiteURL(String value) sq;!5qK
{ S[gACEZ =
sSiteURL = value; 3~Lsa"/
} J0 dY%pH#
Vo6+|ztk|
vsyg u
public String getSFilePath() oeZUd}P
{ UdVf/PGx
return sFilePath; [!>9K}z,=
} 1l/t|M^I
W mbIz[un
'=O1n H<
public void setSFilePath(String value) 8{]nS8i
{ +~BP~
sFilePath = value; 7x=4P|(\}
} @)x*62r+
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^Zp
public String getSFileName() 5]GgjQ
{ -Bl^TT
return sFileName; x N7sFSV@
} i6A9|G$H
AN6Q~%,
z@J>A![m
public void setSFileName(String value) kt0xR)gU
{ eX>*}pI
sFileName = value; Gov.;hy
} qo$ls\[X
&XdTY +
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public int getNSplitter() hkyO_ns
{ 9J~\.:jH-
return nSplitter; }JWkV1
} o$Ylqb#
9pPLOXr ,
/Wcx%P
public void setNSplitter(int nCount) n*Dn{ 7v#z
{ 'l`prp3
nSplitter = nCount; O@ H.k<zn
} 6bc\ )n`
} @D!*@M6
\gkhSLq
u#rbc"
/* a|=^
**Utility.java vG.KSA
*/ q*4U2_^.
package NetFox; \{]y(GT
UlXxG|
>d=pl}-kOQ
public class Utility { Ue60Mf
;2\6U;
SE43C %hv
public Utility() "/RMIS K[;
{ ~bm'i%$k
TTFs|T6`q
~".@;Q
} GB^`A
VH~YwO!x
//线程睡眠 :F@Uq<~(
public static void sleep(int nSecond) "&/2@
{ YvcV801Go
try{ 4xq|
Thread.sleep(nSecond); Z~QLjv&$/r
} tK .1 *
catch(Exception e) 8Z_ 4%vUBg
{ <K<#)mcv
e.printStackTrace (); +-(,'slov
} \>pm (gF
} QK#wsw
^9Cu?!xu0
//日志 A7%/sMv
public static void log(String sMsg) 'Etq;^H
{ :{ZwzJ
System.err.println(sMsg); Q!qD3<?5
} *Cf!p\7!
T@i* F M
d23=WNn
public static void log(int sMsg) 23i2yT
{ G`kz 0Vk
System.err.println(sMsg); U|Gy9"
} __Ksn^I
} "O0xh_Nr
8{/.1:
P_NF;v5v
/* T}=^D=
**TestMethod.java OqDP{X:
*/ Jy%?"wn
package NetFox; k_,& Q?GtU
Fz,jnV9=j
+)WU:aKI
public class TestMethod { >(ip-R
^d{5GK'
-,b+tC<V)0
public TestMethod() =#[oi3k
{ ///xx/weblogic60b2_win.exe P "IR3=
try{ V`#2jDz
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); q)Nw$dW<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); w-# f^#
SiteFileFetch fileFetch = new SiteFileFetch(bean); % g
fileFetch.start(); .kg 3>*
} *j&)=8Y|
catch(Exception e){e.printStackTrace ();} ^}p##7t[
Z:7eroZP
B+U:=591
} WEe7\bWF
4F G0'J&hw
W"_<SYVJ
public static void main(String[] args) [bP^RY:
{ eBnx$
new TestMethod(); tx>7?e8E
} E5)0YYjHZ
} <A8>To<
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