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)); 6I`Lszs
} leSR2os
for(int i=0;i<nEndPos.length-1;i++) {D9m>B3"{
{ C/L+gU&
nEndPos = nStartPos[i+1]; "UDV4<|^k
} Hp!c\z;
nEndPos[nEndPos.length-1] = nFileLength; Q4vl
} f R?Xq@c
} x."/+/
h<8.0
cXY;Tw45
//启动子线程 mqFo`Ee
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 7@*l2edXm+
for(int i=0;i<nStartPos.length;i++) /degBL+
{ UZ` <D/
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S"wn0B$"
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =Pu;wx9
nStartPos,nEndPos,i); xOAA1#
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &>]c"?C*
fileSplitterFetch.start(); V`/D!8>
} tUPdq0%t[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $xl>YYEBMH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); +>uiI4g
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", C%l+<wpXO
nEndPos = " + nFileLength); S[zX@3eZV
// fileSplitterFetch[nPos.length-1].start(); wmQT$`$b
;&N=t64"
vL,:Yn@b
//等待子线程结束 &+v!mw>
//int count = 0; yaD_c;
//是否结束while循环 NEb M>1>^
boolean breakWhile = false; [G/ti&Od^
=KctAR;
ra4$/@3n
while(!bStop) 2sryhS'(H
{ ~dFdO7
write_nPos(); d@?++z
Utility.sleep(500); #OT8_D
breakWhile = true; c{X:0man
--}5%6
" A}S92
for(int i=0;i<nStartPos.length;i++) 6yN8(&`
{ wcI?.
if(!fileSplitterFetch.bDownOver) |\W9$V
{ i:coNK)4
breakWhile = false; `,O#r0m
break; &=-ZNWNo
} ev}ugRxt|k
} P wY~L3,
if(breakWhile) #!i&
break; v3ky;~ke
OdrnPo{
;`f14Fb
//count++; % >\v6ea
//if(count>4) 6|Qg=4_FHt
// siteStop(); /#C}1emK
} dpPu&m+
ZHWxU
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System.err.println("文件下载结束！"); ZVin+z
} $xK2M
catch(Exception e){e.printStackTrace ();} 2`?58&
} 3iI 4yg
BM,]Wjfdj
Ac2,A>
//获得文件长度 \pVmSac,
public long getFileSize() ,3As Ng
{ ruKm_j#J
int nFileLength = -1; eq!>~: #
try{ >$RQ
URL url = new URL(siteInfoBean.getSSiteURL()); 3;hztCZj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hN5?u:
httpConnection.setRequestProperty("User-Agent","NetFox"); Us.")GiHE
~mR@L`"l
pr) `7VuKp
int responseCode=httpConnection.getResponseCode(); R'udC}
if(responseCode>=400) @|jLw($Ly
{ PXRkK63
processErrorCode(responseCode); |g@n'^]
return -2; //-2 represent access is error vo]!IY
} IOjp'6Yr
5x=aJl;G
y$Rr,]L
String sHeader; $Sx(vq6(
FkH HTO
dx&!RK+
for(int i=1;;i++) LrGLIt`
{ =sYUzYm
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); e` QniTkT
//Utility.log(in.readLine()); j+9;Cp]NV
sHeader=httpConnection.getHeaderFieldKey(i); 3!H&bOF
if(sHeader!=null) JdK'~-L
{ _-M27^\vV
if(sHeader.equals("Content-Length")) cOq'MDr
{ zarxv| }$
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JoCZ{MhM
break; KmYSYNr@,
} sYG:\>}ie
} 2:6W_[7l!
else :< d.
break; I0qSx{K
} RnaxRnXVR
} Tx19\\r
catch(IOException e){e.printStackTrace ();} n?[JPG2X
catch(Exception e){e.printStackTrace ();} 9Ev<t\B
5Qh$>R4!"
Z"pCDW)
Utility.log(nFileLength); Q:5^K
4!</JZX~$
bih%hqny
return nFileLength; dKk#j@[n"
} (^@rr[.o7
;J>upI
-91*VBrOd
//保存下载信息（文件指针位置） C$+z1z.!
private void write_nPos() VL?sfG0
{ 'xP&u<(F
try{ $1E'0M`
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2A95vC'u>|
output.writeInt(nStartPos.length); ..K@'*u
for(int i=0;i<nStartPos.length;i++) sy]hMGH:3W
{ 1o8C4?T&
// output.writeLong(nPos); Ov-Y.+L:
output.writeLong(fileSplitterFetch.nStartPos); Hh1]\4D,4
output.writeLong(fileSplitterFetch.nEndPos); F<+!28&h
} [X%Wg:K
output.close(); Z^[ ]s1iP}
} Img$D*BM
catch(IOException e){e.printStackTrace ();} Ym8 V)
catch(Exception e){e.printStackTrace ();} cp)BPg
} */6lyODf
TFAd
3cA'9
//读取保存的下载信息（文件指针位置） * @=ZzL
private void read_nPos() Uk'bOp
{ 1s_N!a
try{ PU2^4h/[`
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); >lV'}0u)
int nCount = input.readInt(); Nrn_Gy>|D
nStartPos = new long[nCount]; KPrH1 [VU
nEndPos = new long[nCount]; &|K9qa~)Y
for(int i=0;i<nStartPos.length;i++) *yZ `aKfH
{ {zTnE?(o`
nStartPos = input.readLong(); YZk.{#^c
nEndPos = input.readLong(); ! }>CEE
} 67g"8R#.V
input.close(); jf^BEz5
} ,gdud[&|;
catch(IOException e){e.printStackTrace ();} Ntt*}|:QV<
catch(Exception e){e.printStackTrace ();} w$DHMpW'
} ]<*-pRN
kRb %:*
/os,s[w
private void processErrorCode(int nErrorCode) }3}H}
{ zMXQfR
System.err.println("Error Code : " + nErrorCode); b]b+PK*h
} ~JS BZ@
`tPVNO,l
8CUlE-R5
//停止文件下载 3oOr*N3R
public void siteStop() 6E#znRi6IE
{ dSI<s^n
bStop = true; we/sv9v}n
for(int i=0;i<nStartPos.length;i++) Ii&\LJ
fileSplitterFetch.splitterStop(); RG.wu6Av
v{X<6^g
.%EYof
} NZ"nG<;5
} \2^o,1r/
//负责部分文件的抓取 +'$5Jtz
**FileSplitterFetch.java SU5O+;{`'
*/ X`fb\}~R(
package NetFox; ka_(8
^D76_'{
WDi2m"
import java.io.*; +ag_w}
import java.net.*; q-s(2C
`=$p!H8
FuM:~jv
public class FileSplitterFetch extends Thread { KL yI*`
Fs3 :NH
zd6F}2*6
String sURL; //File URL G*f\ /
long nStartPos; //File Snippet Start Position h343$,))u
long nEndPos; //File Snippet End Position 2FcNzAaV
int nThreadID; //Thread's ID brX[-
boolean bDownOver = false; //Downing is over $MIDCZ@-
boolean bStop = false; //Stop identical ^ -4~pDv^
FileAccessI fileAccessI = null; //File Access interface 9:P$'y?
<L+1 &H
MD^,"!A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException (6Ciqf8
{ I^Dm 3yz
this.sURL = sURL; N8iLI`
this.nStartPos = nStart; ?>Ngsp>-P
this.nEndPos = nEnd; 2?{'(iay
nThreadID = id; 9:*[Q"v
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6>]w1 H
} ;0U*N& f
aaP6zJXi
}xry
public void run() NBL%5!'
{ H:)_;k
while(nStartPos < nEndPos && !bStop) @^Rl{p
{ UM/!dt}DnF
y 2)W"PuG
la}cGZ; p.
try{ f^ja2.*%?
URL url = new URL(sURL); a^8PB|G
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); '55G:r39
httpConnection.setRequestProperty("User-Agent","NetFox"); I~;w Q
String sProperty = "bytes="+nStartPos+"-"; { V)`6
httpConnection.setRequestProperty("RANGE",sProperty); +0?1"2
Utility.log(sProperty); D4\[D8pD
fDloL
r1TdjnP,2^
InputStream input = httpConnection.getInputStream(); H,c`=Ii3
//logResponseHead(httpConnection); K9-9 c"cz
Cv@)tb
:..WL;gC
byte[] b = new byte[1024]; 5DDSo0E
int nRead; VEpcCK
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tY>Zy1hlI
{ T(qTipq0
nStartPos += fileAccessI.write(b,0,nRead); '#XT[\
//if(nThreadID == 1) 9a @rsyX
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); vz~Oi
} @mJ~?d95v
19U&4Jk
Ta[\BWR2
Utility.log("Thread " + nThreadID + " is over!"); Ia<V\$#
bDownOver = true; )tKSooW
//nPos = fileAccessI.write (b,0,nRead); R+U$;r8l
} e=l:!E10
catch(Exception e){e.printStackTrace ();} M!kSt1
} @H<*|3J
} ''(rC38
:G6aO
|Iwglb!k
//打印回应的头信息 |lcp (u*u
public void logResponseHead(HttpURLConnection con) ="5D}%
{ c6lCF &
for(int i=1;;i++) [_nOo`
{ @TQ/Z$y
String header=con.getHeaderFieldKey(i); qY$ [2]
if(header!=null) $btu=_|f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cS'{h
Utility.log(header+" : "+con.getHeaderField(header)); qDG2rFu&[
else T@=C2 1
break; .9J}Z^FD
} Q`W2\Kod]
} 2lO(f+
^86M94k
f9 \$,7F
public void splitterStop() YrJUs]A
{ !:m.-TE
bStop = true; 2Kf/Id1
} )AxD|A
I/XSW#
p20JUzy
} Scx!h.\5
'Y#'ozSQv
e6>G8d
/* e`S\-t?Z
**FileAccess.java v2E<~/|
*//文件访问(定位，写) -iS^VzI|I
package NetFox; tj'~RQvO
import java.io.*; \yu7,v
-2; 6Pwmv
jLVG=rOn
public class FileAccessI implements Serializable{ yKoZj
_ ,s^
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 _FYA? d}
RandomAccessFile oSavedFile; Hf@4p'
long nPos; e`s1z|h
'9Z`y_~)G
In^mE(8YO
public FileAccessI() throws IOException >7PQOQMW'
{ MzX&|wimb
this("",0); =T,Q7Dh
} 9-/q-,
aTTkj\4
Gk{ 'U
public FileAccessI(String sName,long nPos) throws IOException VaY#_80$s
{ k9f|R*LM
oSavedFile = new RandomAccessFile(sName,"rw"); (0H=f6N
this.nPos = nPos; |67Jw2
oSavedFile.seek(nPos); mLqqo2u
} zQ|2D*W
[9${4=Kq
W06#|8,{v
public synchronized int write(byte[] b,int nStart,int nLen) Zs />_w}
{ YD'gyP4
int n = -1; a1~|?PCbY
try{ aWIkp5BFj
oSavedFile.write(b,nStart,nLen); T2MC`s|`
n = nLen; ;ND$4$
} X7huc*
catch(IOException e) $C;i}q#
{ b^Z2Vf:k]
e.printStackTrace (); ?E"192,z@
} D[/fs`XES
?@9v+Am!
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return n; s|e.mZk/
} ud r\\5
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h(HpeN%`#
} x*7A33@i
"-$}GUK?Z
%-!%n=P
/* M5ZH6X@5
**SiteInfoBean.java 5[jcw`
*/ %-blx)Pc
package NetFox; N:)x67,
Y2x|6{ #
Gu*y7I8
public class SiteInfoBean { 2L~Vr4eHG
Q;$k?G=l
xrPZy*Y,
private String sSiteURL; //Site's URL e'.BTt58Y
private String sFilePath; //Saved File's Path -/pz3n
private String sFileName; //Saved File's Name b^$`2m-?@f
private int nSplitter; //Count of Splited Downloading File ZLT?G
V|MHDMD=
p>7qyZ8
public SiteInfoBean() E+lR&~mK=
{//nSplitter的缺省值为5 &SE}5ddC7
//default value of nSplitter is 5 bgi_QB#k\
this("","","",5); KVa{;zBwl
} E2'Wzrovlo
l&ueD&*4&
PaI\y!f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) TRGpE9i
{ H54RA6$>
sSiteURL= sURL; CW+kKN
sFilePath = sPath; Vc(4d-d5
sFileName = sName; R.rch2
this.nSplitter = nSpiltter; x"Ky_P~
8M*+ |
~a([e\~
} u2oS Ci
zWC| Qe
L;RE5YrH%6
public String getSSiteURL() z< L2W",
{ EfEgY|V0
return sSiteURL; eP@#I^_
} [=>=5'-
_ p\L,No
YGo?%.X
public void setSSiteURL(String value) 4u:SE
{ }gkLO TJ/,
sSiteURL = value; ;d6Dm)/(
} 8gP1]xD
]3O&8,
0V1GX~2
public String getSFilePath() TmG);B}
{ 7%Y`j/
return sFilePath; +-j-)WU?,
} [Arf!W-QG
&>zH.6%$
YCbvCw$Ob
public void setSFilePath(String value) sG`x |%t
{ \_`qon$9
sFilePath = value; \jiE:Qt
} |SkQe[t
L+8ar9es
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public String getSFileName() Xf`e 4
{ u}iuf_
return sFileName; G!Zb27u+
} ,u `xneOs
^X96yj'?
<l<O2l
public void setSFileName(String value) ]I\GnDJ^
{ =P(*j7=
sFileName = value; f!x9%
} ZA(u"T~
Z~J]I|R:
s* (a
public int getNSplitter() >5CK&6
{ (03/4*g_s
return nSplitter; S~Gse+*
} FH=2,"A
Oh! {E5!)
{XOl &
public void setNSplitter(int nCount) \V>5)Rn
{ N{v)pu.
nSplitter = nCount; =LaEEL
} TF8#I28AD
} ^p3GT6
"W7|Xp
B->AY.&j
/* 4C*ywP
**Utility.java KnG7w^
*/ } k2Q
package NetFox; d6J/)nl
v6*0@/L M
MNu0t\`p4
public class Utility { -uYxc=4Lh
;QBS0x\f@
: "85w#r
public Utility() s)E \
{ }X)vktE+|
O%EA,5U.
["3dr@T9Z
} &&&-P\3
+x2JC' -H
//线程睡眠 CYaN;HV@_
public static void sleep(int nSecond) ok\-IU?
{ K0.aU
try{ 8&2+=<Q~
Thread.sleep(nSecond); m Q9dF,
} @su<h\)
catch(Exception e) FP=B/!g
{ c]^P$F8U
e.printStackTrace (); .ck?JXg
} 8c9HJ9vk
} ~+Gh{,f
WE) *~5
//日志 EOB8|:*
public static void log(String sMsg) b >D
{ uVEJV |^/
System.err.println(sMsg); 27SHj9I
} hN3FH#YO
I8bM-k):9R
XFS~
public static void log(int sMsg) (tg.]q_=u
{ l)NkTZ<]
System.err.println(sMsg); +M-tYE 5n
} `\UY5n72
} &e^;;<*w
zZ%[SW&vC
tj13!Cc}e`
/* 0ID9=:J
**TestMethod.java Z*k(Q5&U
*/ k'o[iKlu
package NetFox; J0!V(
1B;2 ~2X
RcYUO*
public class TestMethod { Rl ]x:
.iy4 (P4
^+>*Y=fl
public TestMethod() cB uuq
{ ///xx/weblogic60b2_win.exe @ VWED
try{ w ,j*I7V
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); h3@tZL#g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~q ^o|?
SiteFileFetch fileFetch = new SiteFileFetch(bean); OFtaOjsyUa
fileFetch.start(); b G:\*1T
} U`(=iyWP=
catch(Exception e){e.printStackTrace ();} CTNL->
,U\s89
$?56 i4
} t{>K).'
cfIC(d
=dGp&9K,fw
public static void main(String[] args) pCE GZV,d@
{ B7f<XBU6>
new TestMethod(); \GL] I.
} Jpapl%7v
} (h0@;@@7hW
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