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)); &W_th\%
} 4be> `d5j
for(int i=0;i<nEndPos.length-1;i++) 4!%]fg}Um
{ k0K A~
nEndPos = nStartPos[i+1]; 744=3v
} 9{J?HFw*;
nEndPos[nEndPos.length-1] = nFileLength; w$Ux?y-L
} mX_)b>iW
} 1 tfYsg=O
N_'+B+U?
#a}N"*P
//启动子线程 s"mFt{Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; H:}}t]E
for(int i=0;i<nStartPos.length;i++) lJ/6-dP
{ ~Yk"Hos
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +mWjBY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }5S2p@W)
nStartPos,nEndPos,i); Dt}dp_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ??xlA-E
fileSplitterFetch.start(); ?vbDB4
} [!+D<Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), g{ (@uzqG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?iz<
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", OhWC}s
nEndPos = " + nFileLength); |$w*RI0C
// fileSplitterFetch[nPos.length-1].start(); 19y 0$e_V
OXtBJYe
)mD\d|7f
//等待子线程结束 pDDG_4E>
//int count = 0; !RMS+Mm?
//是否结束while循环 i&F~=Q`
boolean breakWhile = false; fGO*%)
Z;*`fd?8
v5Y@O|i#
while(!bStop) pcpxe&S
{ kyAs'R@z
write_nPos(); b.Su@ay@(^
Utility.sleep(500); oI$V|D3 9
breakWhile = true; RK)l8c}
2ij/N%l
U>3 >Ex
for(int i=0;i<nStartPos.length;i++) wXCyj+XB*
{ {visv{R<
if(!fileSplitterFetch.bDownOver) 75Fp[Q-
{ -N^=@Yx)
breakWhile = false; ' o=E!?
break; 22bT3
} @a;sV!S{
} >\\5"Sf
if(breakWhile) Vu|dV\N0*
break; m.146
m^0A?jBrR
Qv!rUiXq
//count++; pGk"3.ce
//if(count>4) eiB(VOJ
// siteStop(); ]L]T>~X`
} |>JmS
24|<<Xn
;$6x=uZ
System.err.println("文件下载结束！"); 5`yPT>*#m>
} }9}w8R~E
catch(Exception e){e.printStackTrace ();} N[ Q#R~Hn<
} f(.6|mPp
sN@j5p^jc
MgP{W=h2
//获得文件长度 Jk~UEqr+
public long getFileSize() >Jiij
{ jaa/k@OG
int nFileLength = -1; 8l?w=)Qy
try{ =#'+"+lQ }
URL url = new URL(siteInfoBean.getSSiteURL()); GU#Q}L2
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >0M:&NMda
httpConnection.setRequestProperty("User-Agent","NetFox"); uE"2kn
z@n+7p`w
Sgx+V"bkT
int responseCode=httpConnection.getResponseCode(); wLSjXpP8
if(responseCode>=400) }!knU3J
{ aKOf;^@
processErrorCode(responseCode); ,E]|\_]
return -2; //-2 represent access is error FLEg0/m0
} 6NSO>/E
o@@_J@}#
"?+UI
String sHeader; lYdQB[l
jqqaw
jQ^Yj"6
for(int i=1;;i++) :%>oe> _"
{ yI *M[0
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); q|/!0MU"
//Utility.log(in.readLine()); !r2}59J
sHeader=httpConnection.getHeaderFieldKey(i); =_pmy>_z
if(sHeader!=null) .Wh6(LDY(
{ Q%$i@JH`m
if(sHeader.equals("Content-Length")) M3PVixli3
{ }kv)IJ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Tu'E{Hw
break; +E)e1:8
} `^`9{@~
} 2}>go^#O/w
else }o{!}g9
break; .8%vd
} ?^eJ:
} f5N<3m=
catch(IOException e){e.printStackTrace ();} w[M5M2CF
catch(Exception e){e.printStackTrace ();} Hq79/wKj
QZ:v
;7)OSGR
Utility.log(nFileLength); AV9:O{
P)4x
89ZDOji?O
return nFileLength; XuA0.b%
} e ^-3etx
ul}4p{ m[
vN'VDvVM
//保存下载信息（文件指针位置） O} (E(v
private void write_nPos() |#!eMJ&0
{ ./2Z?,
try{ \(wn@/yP'
output = new DataOutputStream(new FileOutputStream(tmpFile)); 1.uUMW
output.writeInt(nStartPos.length); KgL<}=S
for(int i=0;i<nStartPos.length;i++) +i2YX7Of
{ rR3m'[
// output.writeLong(nPos); EF0Pt
output.writeLong(fileSplitterFetch.nStartPos); `g2&{)3k
output.writeLong(fileSplitterFetch.nEndPos); 6{lG1\o
} '=-s1c@^
output.close(); b^+Fs
} 7BVXBw
catch(IOException e){e.printStackTrace ();} G)4ZK#wz
catch(Exception e){e.printStackTrace ();} ipgN<|`?@
} B?!9W@
.$n$%|"H-
w 5!ndu
//读取保存的下载信息（文件指针位置） KC#kss
private void read_nPos() J,.j_ii`!
{ WFQ*s4 R(
try{ ;,()wH
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5XhK#X%:A
int nCount = input.readInt(); i#Ne'q;T
nStartPos = new long[nCount]; ll 6]W~[ZC
nEndPos = new long[nCount]; EaJDz`T}
for(int i=0;i<nStartPos.length;i++) ~r{\WZ.
{ J~M H_N
nStartPos = input.readLong(); |;X?">7NW
nEndPos = input.readLong(); N:"M&EUM
} s0_-1VU
input.close(); ab8oMi`z
} m*Q[lr=
catch(IOException e){e.printStackTrace ();} Q@ykQ
catch(Exception e){e.printStackTrace ();} L?AM&w-cg9
} ecM4]U
"``W6W-(
^uKnP>*l
private void processErrorCode(int nErrorCode) wpAw/-/
{ LuQ"E4;nY%
System.err.println("Error Code : " + nErrorCode); pE$|2v
} >_|Z{:z]d.
Q$/V)0
]J8KCjq@
//停止文件下载 G5y]^P
public void siteStop() 82G lbd)
{ >DPds~k
bStop = true; V:nMo2'hb
for(int i=0;i<nStartPos.length;i++) GhSL%y
fileSplitterFetch.splitterStop(); 7yc9`j}]
*%P>x}6w3
^.ZSpc}<
} JUe K"|fA
} CwTS/G
//负责部分文件的抓取 0BbiQXU
**FileSplitterFetch.java !$%/ rQ9
*/ [q0_7
package NetFox; u|]mcZ,ZW
] P:NnKgK
[=]+lei
import java.io.*; 7,) 67G;
import java.net.*; +1E?He:iQ
$gj+v+%N
qcR|E`k-G
public class FileSplitterFetch extends Thread { t~+{Hr) #y
RT8_@8
c,3'wnui
String sURL; //File URL 0})7of
long nStartPos; //File Snippet Start Position xI.Orpw
long nEndPos; //File Snippet End Position 4?P%M"\Iv
int nThreadID; //Thread's ID Fi?U)T+%+
boolean bDownOver = false; //Downing is over lp37irI:
boolean bStop = false; //Stop identical JLFFh!J
FileAccessI fileAccessI = null; //File Access interface J};u25:}
A{DIp+
WI*^+E&=*
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -dc"N|.
{ lOWB^uS%
this.sURL = sURL; 9^#zxmH)
this.nStartPos = nStart; pXpLL_
this.nEndPos = nEnd; JxMyeo%gv
nThreadID = id; -z>Z0viA
fileAccessI = new FileAccessI(sName,nStartPos);//定位 _rWM]
} c5T~0'n
{UV<=R,E
Lic{'w&
public void run() <Y}"D Yt
{ Ti9:'I
while(nStartPos < nEndPos && !bStop) ZTgAZ5_cz
{ ;*<{*6;=?
Nf/hr%jL
CA~em_dC
try{ 0x3 h8fs
URL url = new URL(sURL); l1+w2rd1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q%X:5G?
httpConnection.setRequestProperty("User-Agent","NetFox"); kb>Vw<NtE
String sProperty = "bytes="+nStartPos+"-"; :uU]rBMo
httpConnection.setRequestProperty("RANGE",sProperty); [t"_}t=w
Utility.log(sProperty); 6,V.j>z
A9fjMnw
m-Z'K_oQ
InputStream input = httpConnection.getInputStream(); c1)BGy li
//logResponseHead(httpConnection); OTNZ!U/)j
Hz!U_?
Z,N7nMJf
byte[] b = new byte[1024]; <manv8*6
int nRead; 3H\b N4
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) e@2E0u4
{ ;QvvU[eb
nStartPos += fileAccessI.write(b,0,nRead); laD.or
//if(nThreadID == 1) &8:iB {n
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [`Qp;_K?t
} Gct&}]3pm
0%qctZy
^Q43)H0
Utility.log("Thread " + nThreadID + " is over!"); 3u"J4%zg|L
bDownOver = true; \ eyQo>(
//nPos = fileAccessI.write (b,0,nRead); NXWIE4T>*^
} QvK]<HEr
catch(Exception e){e.printStackTrace ();} DS[l,x
} )=,9`+Zta
} u #=kb5}{
Qn'r+X5t
3 4A&LBwC
//打印回应的头信息 l b1sV
public void logResponseHead(HttpURLConnection con) [6RV'7`Abj
{ +*:x#$phx
for(int i=1;;i++) !Wdt:MUI8
{ ]X"i~$T1S
String header=con.getHeaderFieldKey(i); L[QI 5N
if(header!=null) "PDSqYA
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +n8I(l=
Utility.log(header+" : "+con.getHeaderField(header)); )l[7;ZIw$
else Vbqm]2o&
break; 1=o(sIeA
} 3' :[i2[
} Bgo"JNM
79c9+
<'4!G"_EP
public void splitterStop() $U"P+
{ D\_*,Fc
bStop = true; b3 %&
} Ph!KL\
jQK2<-HZ3
0t:|l@zB
} v^lm8/}NO
Y(G*Yi?;
d)17r\*>I
/* 5f^`4pT
**FileAccess.java fB @pwmu
*//文件访问(定位，写) 1!v >I"]
package NetFox; ]5)&36
import java.io.*; 5x1jLPl'
3/SqXu
E{k%d39>
public class FileAccessI implements Serializable{ L[[H&#\
A0N ;VYv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ~_l:b
RandomAccessFile oSavedFile; 0or6_y6
long nPos; h?pGw1Q
2sd=G'7!
b09#+CH?
public FileAccessI() throws IOException |\r\i&|g1
{ L+0N@`nRF
this("",0); l<)JAT;P
} (m =u;L"o
$Bwvw)(%
;KjMZ(Iil1
public FileAccessI(String sName,long nPos) throws IOException qU x7S(a
{ EBn:[2
oSavedFile = new RandomAccessFile(sName,"rw"); Vo9)KxR
this.nPos = nPos; abk:_
oSavedFile.seek(nPos); WG[0$j
} C7*Yg$`{
0?4^.N n3
V\7u
public synchronized int write(byte[] b,int nStart,int nLen) bM3'm$34
{ 2Nt]Nj`
int n = -1; MT#[ -M\
try{ 7zkm
oSavedFile.write(b,nStart,nLen); K?9H.#(
n = nLen; $m%/veD k
} AdN=y8T
catch(IOException e) @ :
{ C`1\$U~%
e.printStackTrace (); DkMC!Q\
} @SVEhk#
GPhwq n{
[r< Y0|l,m
return n; V{aIhH>P
} }y=n#%|i.
P@T $6%~
/7HIL?r
} fO}1(%}d
W,oV$ s^
wCEfR!i
/* +VI0oo {Z
**SiteInfoBean.java wYxFjXm
*/ >8HRnCyp/
package NetFox; ljR?* P
P9HPr2
* jNu?$
public class SiteInfoBean { P*^UU\x'4I
GMp'KEQQ
AxqTPx7`|
private String sSiteURL; //Site's URL "@<g'T0
private String sFilePath; //Saved File's Path /)<7$
private String sFileName; //Saved File's Name [~r$US
private int nSplitter; //Count of Splited Downloading File nv|y@!(
<h>fip3o
"kuBjj2
public SiteInfoBean() W;xLuKIG
{//nSplitter的缺省值为5 kd2'-9
//default value of nSplitter is 5 @P*P8v8:
this("","","",5); ).#D:eO[~
} %;XuA*e
;og<eK
n#AH@`&i
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Vh-h{
{ )t 7HioQ
sSiteURL= sURL; I Y-5/
sFilePath = sPath; :95_W/l
sFileName = sName; V\lF:3C
this.nSplitter = nSpiltter; JG+o~tQC
Gqu0M`+7
oM7-1O
} o+23?A~+
YO4ppL~xe
'$nGtB5
public String getSSiteURL() j3'/jk]\
{ ^Q+5M"/8
return sSiteURL; 9Yne=R/]
} {y%O_-C'r
,UJPLj^
n7<-lQRaxZ
public void setSSiteURL(String value) Xpz-@fqKdf
{ .TU15AAc
sSiteURL = value; 8pKPbi;(2
} !LSWg:Ev+
#z5?Y2t7~^
$f-pLF+x
public String getSFilePath() e/~<\
{ wA+4:CF@
return sFilePath; VFp)`+8
} RR {9
[9Hm][|Ph
fC:\Gh5
public void setSFilePath(String value) f*f9:xUY
{ UE](`|4H
sFilePath = value; *VAi!3Rx;
} "@bk$o=
b<MMli
;{u#~d}
public String getSFileName() ( I~XwP&
{ 8#3cmpx4
return sFileName; b8Ad*f\
} iFT3fP'> 5
4SO{cst
: .eS|
public void setSFileName(String value) *J-jr8&
{ N^j''siB
sFileName = value; PU\q.y0R
} rMx_ <tXX
AYtcN4\/
a.ME{:a%
public int getNSplitter() 667tL(
{ eNKdub
return nSplitter; ~0t'+.
} qt)mUq;>
sMo%Ayes
Wsz9X;
public void setNSplitter(int nCount) ?|F;x"
{ 3Q6#m3AWY
nSplitter = nCount; _dY}86{
} KWkT 9[H
} ~#xRoBy3
RozsRt;i
2^j9m}`
/* +w/o
**Utility.java Zz ?y&T
*/ x@x@0k`A2
package NetFox; :\cJvm
lKSI5d
\p|!=H@
public class Utility { T{Q&}`D)r
<i?-x&Q?=
Sa(rl^qZ2
public Utility() &0blHDMj{#
{ (6aZQ`H
uSbg*OA
}gt~{9?c
} ,4UJ|D=J
3`I_
//线程睡眠 0<;B2ce
public static void sleep(int nSecond) vpMv
{ auv\fR :
try{ an$h~}/6:
Thread.sleep(nSecond); Mqy`j9FbL
} Ku# _
catch(Exception e) ;W"[,#2TM
{ a+Nd%hoe
e.printStackTrace (); A`8If
} ]+S QS^4
} )FCqYCfk
n(MEG'9}
//日志 I!bZ-16X
public static void log(String sMsg) y%AJ>@/;
{ \FM- FQK
System.err.println(sMsg); 1+#8} z:
} yLX\pkAt4
|0 VP^md
{,X(fJ
public static void log(int sMsg) sa?;D
{ %stktVDAP
System.err.println(sMsg); b /ySt<
} 4j{ }{
} ^6n]@4P
HBu>BSv:
=Ch#pLmH
/* Li^V?
**TestMethod.java oPV"JGa/B4
*/ .:/@<V+K
package NetFox; q\"$~*
]QQ"7_+
^m9cEl^:nQ
public class TestMethod { XQPJ(.G
0]HIc
Wov_jVdN\
public TestMethod() ZG|T-r;~
{ ///xx/weblogic60b2_win.exe c9'b`#'
try{ Ws@s(5r
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9p<l}h7g
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ??;[`_h{bz
SiteFileFetch fileFetch = new SiteFileFetch(bean); }Q_i#e(S
fileFetch.start(); v]>(Ps )R
} 8'$n|<1X
catch(Exception e){e.printStackTrace ();} y.2 SHn0
N3)EG6vE*
.nJGxz+X"
} `pr,lL
Z$@Nzza-
U# gmk0>t{
public static void main(String[] args) Zuf&maa S
{ dX*PR3I-3
new TestMethod(); !k) ?H* ^@
} :gn!3P}p?
} Qp}<8/BM\
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