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)); 8,@0~2fz#
} u|"y&>!R-
for(int i=0;i<nEndPos.length-1;i++) lFtH;h,==v
{ dI+Y1Vq
nEndPos = nStartPos[i+1]; _]v@Dq VP
} x,NV{uG$n
nEndPos[nEndPos.length-1] = nFileLength; 4_P6P
} "F=ta
} 6]r#6c%
!o`riQLs>
r]0>A&,
//启动子线程 vRh)o1u)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; )7C+hQe
for(int i=0;i<nStartPos.length;i++) W m&*
{ 0`/CoP<U
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q{|_"sfJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `mthzc3W
nStartPos,nEndPos,i); wQ^RXbJI9
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); oFb~|>d
fileSplitterFetch.start(); .~C%:bDnX7
} EK&";(x2(
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a>Wr2gPko
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *X5<]{7c
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <0!<T+JQ
nEndPos = " + nFileLength); ;i?rd f
// fileSplitterFetch[nPos.length-1].start(); G<-<>)zO!
Hqtv`3g
)(9[>_+40
//等待子线程结束 ^z`d2it
//int count = 0; 3bRW]mP8
//是否结束while循环 fg7
boolean breakWhile = false; 7|xu)zYB
WMa`!Q
Y P,>vzW
while(!bStop) ?AO22N|j
{ K$l@0r ~k
write_nPos(); j}O qWX>/
Utility.sleep(500); ]N2! 'c
breakWhile = true; D*>#]0X
QHxof7
;F_P<b 2
for(int i=0;i<nStartPos.length;i++) \.'[!GE*c
{ 1Va=.#<
if(!fileSplitterFetch.bDownOver) F9"Xu-g
{ Z~w2m6;s
breakWhile = false; O!t=,F1j
break; IhN^*P:Fo
} LzxO=+=9!q
} zGdYk-H3TH
if(breakWhile) /'/i?9:
break; 4jc?9(y%
vjzG H*
5Bt~tt
//count++; $<9u:.9xf
//if(count>4) AhkDLm+
// siteStop(); b!e0pFS;
} LJ6l3)tpD
zwU1(?]I{
t,n2N13
System.err.println("文件下载结束！"); W~PMR/^i
} Yw yMCd
catch(Exception e){e.printStackTrace ();} rog1
} l3*GQ~m7
q65]bs4M
$Dd-2p
//获得文件长度 -&Q+x,.%
public long getFileSize() artn _
{ dz^b(q
int nFileLength = -1; P,xIDj4d
try{ ^?wR{q"8
URL url = new URL(siteInfoBean.getSSiteURL()); M.xZU\'ty
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); D2GF4%|
httpConnection.setRequestProperty("User-Agent","NetFox"); }'?qUy3x
8A5/jqnqt
SdN&%(ZE
int responseCode=httpConnection.getResponseCode(); EDuH+/:n
if(responseCode>=400) @q`T#vd
{ 5dhy80|g]
processErrorCode(responseCode); oaZdvu@y
return -2; //-2 represent access is error C_'EO<w$
} E[7E%^:Mg
q(X7e
WNZYs
String sHeader; ( et W4p
6O,:I
in5e *
for(int i=1;;i++) l p(D@FT
{ -Lq2K3JHyn
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); V1,/qd_
//Utility.log(in.readLine()); g*(z.
sHeader=httpConnection.getHeaderFieldKey(i); LuHRB}W
if(sHeader!=null) ;aj;(Z.p)
{ AloL+eN@
if(sHeader.equals("Content-Length")) pF7N = mO
{ <f`n[QD2z
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }#-@5["-X
break; `N&*+!O%
} ^{{a v?h
} q)f_!N
else Bz <I7h
break; )0/*j]Kf
} nF_q{e7
} AorY#oq
catch(IOException e){e.printStackTrace ();} L N Fe7<y
catch(Exception e){e.printStackTrace ();} j"'a5;Sy
a5R. \a<q
MPDRMGR@i
Utility.log(nFileLength); <R+?>kz6
l S3LX
L"/?[B":
return nFileLength; )bR0>3/
} BWvM~no
x.Egl4b3
%)r:!R~R
//保存下载信息（文件指针位置） J <;xkT1x
private void write_nPos() iCA-X\E
{ lVQE}gd%m
try{ (9oo8&GG
output = new DataOutputStream(new FileOutputStream(tmpFile)); j7MUA#6$
output.writeInt(nStartPos.length); !tt 8-Y)i
for(int i=0;i<nStartPos.length;i++) hRRxOr#*$
{ H la?\
// output.writeLong(nPos); u z7|!G!43
output.writeLong(fileSplitterFetch.nStartPos); C0KFN
output.writeLong(fileSplitterFetch.nEndPos); 7Mq{Py1
} Il9xNVos#
output.close(); Y,GlAr s4
} CQNMCYjg(R
catch(IOException e){e.printStackTrace ();} <tBT?#C9+
catch(Exception e){e.printStackTrace ();} 9 " t;6
} z@,(^~C_
Z$g'h1,zW
vanV|O
//读取保存的下载信息（文件指针位置） [5p3:D
private void read_nPos() l"(PP3
{ 5I,NvHD4
try{ yf0v,]v[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); pi~5}bF!a
int nCount = input.readInt(); as]M%|/-I
nStartPos = new long[nCount]; Im\ ~x~{
nEndPos = new long[nCount]; z,$uIv}'@
for(int i=0;i<nStartPos.length;i++) S6(48/
{ @--"u_[
nStartPos = input.readLong(); |'1.ajxw
nEndPos = input.readLong(); Jz>P[LcB
} Za1mI^ L1
input.close(); [ i,[^
} E"_{S.Wc
catch(IOException e){e.printStackTrace ();} 1HKA`]D"p
catch(Exception e){e.printStackTrace ();} 0?8>{!I
} _hyqHvP
-&`_bf%M
E b:iym0
private void processErrorCode(int nErrorCode) i+mU(/l2{
{ K<:%ofB"S
System.err.println("Error Code : " + nErrorCode); c5$DHT@N"
} (J%4}Dm
] 1pIIX}
V\x'w*FP
//停止文件下载 2,q*8=?{6P
public void siteStop() ?k4Hk$V
{ dp^PiyL
bStop = true; gJr)z7W'8
for(int i=0;i<nStartPos.length;i++) )W 5g-@
fileSplitterFetch.splitterStop(); t`E5bWG
]o]`X$n
JyTETf,y
} Ewp2 1
} B G\)B
//负责部分文件的抓取 )K@D4sl
**FileSplitterFetch.java e-P{)L<s5
*/ H[p~1%Lq
package NetFox; Ar~/KRK
-rI7ihr*
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import java.io.*; e|~{X\l
import java.net.*; y>0 @.
"lu^
Bo8f52|
public class FileSplitterFetch extends Thread { Z(tJd,
:*,!gf
D((/fT)eD
String sURL; //File URL )s^gT]"N
long nStartPos; //File Snippet Start Position nVWU\$Ft
long nEndPos; //File Snippet End Position eA2*}"W
int nThreadID; //Thread's ID 0J'Cx&Rg
boolean bDownOver = false; //Downing is over Zf}2c8Vc4
boolean bStop = false; //Stop identical W|@SXO)DY
FileAccessI fileAccessI = null; //File Access interface 72xf|s=
g]HWaFjc5
T88$sD.2 '
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 4qsct@K,
{ r9u'+$vmF
this.sURL = sURL; q`{@@[/(y
this.nStartPos = nStart; w9GY/]
this.nEndPos = nEnd; 75^*4[
nThreadID = id; Gdb0e]Vt+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 5)S;R,
} A\rY~$Vr
#aC&!Rei{
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public void run() D9NRM;v
{ +qjZ;5(
while(nStartPos < nEndPos && !bStop) *!"T^4DEg
{ > `eo0
ufR>*)_+
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try{ O}cfb4"
URL url = new URL(sURL); _){u5%vv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); |tI{MztJ"c
httpConnection.setRequestProperty("User-Agent","NetFox"); B&X)bGx8
String sProperty = "bytes="+nStartPos+"-"; J+ :3==,
httpConnection.setRequestProperty("RANGE",sProperty); 6Zw$F3 <
Utility.log(sProperty); u;^H=7R
[= E=H*j
vFJ4`Gjw(
InputStream input = httpConnection.getInputStream(); HI D6h!
//logResponseHead(httpConnection); UV;I6]$}A7
l2Py2ZI-b
b_{+OqI
byte[] b = new byte[1024]; `k I}p
int nRead; KS~Q[-F1P
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) &f'Lll
{ hOLlZP+
nStartPos += fileAccessI.write(b,0,nRead); Om:Gun\%
//if(nThreadID == 1) 1iR\M4?Frf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #Qz9{1\G
} K ~\b+
qfFa" a
EMH-[EBx
Utility.log("Thread " + nThreadID + " is over!"); EiM\`"o
bDownOver = true; ~8k`~t!
//nPos = fileAccessI.write (b,0,nRead); ]A-LgDsS
} jK6dI 7h
catch(Exception e){e.printStackTrace ();} |Zn,|-iW
} %iIr %P?
} kH0kf-4\
lp$,`Uz`
j/uMSE
//打印回应的头信息 epk C'
public void logResponseHead(HttpURLConnection con) 8[^b8^
{ E]a,2{&8<
for(int i=1;;i++) l3MA&&++KF
{ 2g)q (
String header=con.getHeaderFieldKey(i); 8j&1qJx)
if(header!=null) U.^%7.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Q"pZPpl&
Utility.log(header+" : "+con.getHeaderField(header)); -y&>&D
else u^ wGVg
break; 4yxf/X)
} !&KE">3Qu
} 65&+Fv
}VH`\g}
= "Lb5!
public void splitterStop() Jn?ZJZ
{ P6^\*xkMr
bStop = true; ='eQh\T)
} 9J49s1
2+(SR.oGq
fEK%)Z:0
} )J\ JAUj
$Ovq}Rexc
:Z;kMrU
/* "NSY=)fV
**FileAccess.java p_g8d&]V
*//文件访问(定位，写) P)=$0kR3
package NetFox; =snJ+yn!
import java.io.*; bb/A}< zD
m:;`mBOc3
#{bT=:3a
public class FileAccessI implements Serializable{ 4%jSqT@
v>Kv!OY:c
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ir)~T0
RandomAccessFile oSavedFile; Vc|QW
long nPos; Mm"0Ip2"
[ dVRVm0N
m<4tH5};d
public FileAccessI() throws IOException W6*5e{
{ kf",/?s2Z
this("",0); H8qAj
} 3AuLRI
L{6Vi&I84[
$>l65)(E\
public FileAccessI(String sName,long nPos) throws IOException <M3&\
{ NydoX9
oSavedFile = new RandomAccessFile(sName,"rw"); gAGcbepX
this.nPos = nPos; <^A1.o<GN
oSavedFile.seek(nPos); 9@p+g`o
} g7LS
7tT L,Nxe
wAF#N1-k
public synchronized int write(byte[] b,int nStart,int nLen) VelX+|w
{ l) )Cvre+
int n = -1; R^4 j0L
try{ @JD!.3
oSavedFile.write(b,nStart,nLen); 7bam`)n
n = nLen; %Zu+=IZ
} o:/ymeG
catch(IOException e) 8bEii1EM
{ { r8H5X
e.printStackTrace (); oJ}$ /_
} /u'M7R
b;(BMO,(
O#D N3yu?
return n; {D8[pG%z
} pB]+c%\
-+|{#cz
]M9r<x*
} ZEU/6.
^5gB?V,
|f&=9%
/* &uTK@ G+
**SiteInfoBean.java 7;:Uv=
*/ o>4GtvA*
package NetFox; ?pF uV`Zm
<NX6m|DD
M$GZK'%
public class SiteInfoBean { Jp`qE
ulnlRx
PEAo'63$
private String sSiteURL; //Site's URL T .L>PL?=
private String sFilePath; //Saved File's Path )eSD5hOI)
private String sFileName; //Saved File's Name 1:iT#~n
private int nSplitter; //Count of Splited Downloading File ?`D/#P
XFN4m #
V\o&{7!
public SiteInfoBean() 0j|JyS:}G
{//nSplitter的缺省值为5 @460r
//default value of nSplitter is 5 PP)-g0^@
this("","","",5); W[tX%B
} ::rKW*?
!@-g9z
KF`@o@,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zz+[]G+"2m
{ )y}W=Q>T
sSiteURL= sURL; 4~/3MG
sFilePath = sPath; T]Eg9Y:+v
sFileName = sName; Tj*Vk $}0
this.nSplitter = nSpiltter; t1tZ:4
o@0p
8L*P!j9`EY
} CR<Nau>
_!*??B6u
n$y)F} .-
public String getSSiteURL() 4!KUPgg
{ OmX(3>:9
return sSiteURL; ?KfV>.()
} uCNi&.
5}t}Wc8
(>\w8]
public void setSSiteURL(String value) ww"HV;i
{ -F|C6m!
sSiteURL = value; 6>Szxkz
} >A;9Ee"&
]RJcY1
5 J9,/M0
public String getSFilePath() )9QeVf
{ k9<P]%
return sFilePath; ]2P*Z6Az
} L.@o
.-g++f(_i
#{kwl|c
public void setSFilePath(String value) \{ui{8+G
{ nZ 0rxx[V?
sFilePath = value; U&\8~h
} jQiKof>
do1aH$Iw
2=6}! Y
public String getSFileName() IA XoEBlMs
{ 80M"`6
return sFileName; eD4o8[s
} *h>KeIB;
]D;X"2I2'b
ED={OZD8
public void setSFileName(String value) C&vUZa[p
{ MZX-<p+
sFileName = value; }G#TYF}
} 3i'L5f67
Xn'{g
26,!HmtC
public int getNSplitter() CcZ\QOet&C
{ lklMdsIdj
return nSplitter; M8BN'%S
} Ok=RhoZZ
iwl\&uNQU
[y}0X^9,E
public void setNSplitter(int nCount) ;r_YEPlZ
{ 2R!1Vl
nSplitter = nCount; RTW4r9~'
} =;9*gDfD
} /{';\?w
2,Og(_0>
f@%H"8w!
/* m|)Mc VV
**Utility.java C[ ehw
*/ I'h6!N"
package NetFox; 0P<bS?e<l
jcWv&u|
w{t2Oo6Q0+
public class Utility { _BV'J92.
9oK#n'hjb
=!b<@41
public Utility() G02(dj
{ 1{8SKfMdP
PyD'lsV
vPn(~d_
} *.UM[Wo
6p X[m{
//线程睡眠 Jbud_.h9
public static void sleep(int nSecond) $Q[a^V~:
{ ^;b$`*M1
try{ YI=03}I
Thread.sleep(nSecond); %8)GuxG*
} tTT./-*0
catch(Exception e) )pS1yYLj
{ 4|ryt4B
e.printStackTrace (); aD aQ7i
} 0B^0,d(s
} CF`tNA3fxm
ik@g;>pQD
//日志 S(^*DV
public static void log(String sMsg) ]OE{qXr{
{ 0jsU^m<g
System.err.println(sMsg); 9OeY59 :
} :h1-i
0Dj<-n{9
;IC:]Zu
public static void log(int sMsg) HB+\2jEE
{ +)C?v&N
System.err.println(sMsg); QfuKpcT&
} 5G@z l
} p!MOp-;-
P#/k5]g
#<X+)B6t
/* U5; D'G
**TestMethod.java OTA@4~{C
*/ FnN@W^/z
package NetFox; 85rXm*Df
qNP&f8fH
&D "$N"
public class TestMethod { N4$!V}pp
v,N*vqWS
7(;M
public TestMethod() _L mDF8Q(
{ ///xx/weblogic60b2_win.exe X6jW mo8]
try{ }yup`R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Y%v?ROql
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =@U~sl[
SiteFileFetch fileFetch = new SiteFileFetch(bean); b{|Ha3;w
fileFetch.start(); Yyq:5V!
} NPws^
catch(Exception e){e.printStackTrace ();} -hav/7g
Y_3{\g|x
uFDJRQJ<
} %oasIiO
'u }|~u?m
SomA`y+ERn
public static void main(String[] args) F V8K_xj
{ M),i4a?2
new TestMethod(); wu5]S)?*
} Pa%;[hbn
} */iD68r|-
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