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)); }ec3qZ@
} k9 NPC"
for(int i=0;i<nEndPos.length-1;i++) |;MW98 A
{ TOXZl3s5#
nEndPos = nStartPos[i+1]; i+eDBg6
} /eNDv(g)M
nEndPos[nEndPos.length-1] = nFileLength; muKCCWy#
} "%]vSr
} { K*
;;lOu~-*$p
i :Sih"=
//启动子线程 JWo).
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~sbn"OS+
for(int i=0;i<nStartPos.length;i++) 19 <Lgr
{ `}|$eF&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^.~m4t`U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 9 `z^'k&
nStartPos,nEndPos,i); yjj)+eJ(Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J\c\Ar:
fileSplitterFetch.start(); !;h`J:dN
} /w2jlu}yt
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >^ijj`{d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SWPb=[WEz
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6P U]I+
nEndPos = " + nFileLength); uhO-0H
// fileSplitterFetch[nPos.length-1].start(); ]iE)8X
_8'z"wF
w!~85""
//等待子线程结束 8KyF0r?
//int count = 0; "Iwd-#;$;
//是否结束while循环 2JX@#vQ4
boolean breakWhile = false; UhVJ!NrT
DfV'1s4y
K6M_b?XekA
while(!bStop) jz"-E
{ jpRC6b?
write_nPos(); To@77.'
Utility.sleep(500); o=ULo &9
breakWhile = true; Qa-~x8]
)h,-zAnZ
M&~cU{9c
for(int i=0;i<nStartPos.length;i++) n+%tu"e
{ F=l.2t*9
if(!fileSplitterFetch.bDownOver) :elTqw>pn
{ H!vX#
breakWhile = false; &L`yX/N2
break; 'e5,%"5(c
} iyr'9BA
} #) bqn|0l
if(breakWhile) :Co+haW
break; )*T<s
VH2/
9Ls=T=96
//count++; (X(c.Jj
//if(count>4) IM9P5?kJ ?
// siteStop(); ~zD*=h2C
} =V*4&OU
@(_f}SgfE
ruTj#tWSo
System.err.println("文件下载结束！"); 2#g4R
} '1te(+;e@
catch(Exception e){e.printStackTrace ();} z}f;_NX
} ^#)M,.G^
N_qKIc_R
>$dkA\&p
//获得文件长度 bk{.9nz2
public long getFileSize() -|x YT+?%
{ ;1[Lwnm
int nFileLength = -1; Oxq} dX7S
try{ 8w]>SEGFs
URL url = new URL(siteInfoBean.getSSiteURL()); r(ufyC&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O| zLD
httpConnection.setRequestProperty("User-Agent","NetFox"); X"pp l7o
oYNp0Hc
[5O`
int responseCode=httpConnection.getResponseCode(); ps=+wg?]
if(responseCode>=400) /'g"Ys?3
{ kx_PMpc
processErrorCode(responseCode); h`HdM58CQ
return -2; //-2 represent access is error E+|r h-M7
} 'I *&P5|
}j /r
1[Ffl^\ARp
String sHeader; *N|s+
n]+v Eu|
-yn;Jo2-
for(int i=1;;i++) b/dyH
{ YMEI J}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jQ[M4)>_k`
//Utility.log(in.readLine()); oy!Dm4F
sHeader=httpConnection.getHeaderFieldKey(i); eg vgi?y
if(sHeader!=null) 'ffOFIz|=I
{ h]z>H~.<*
if(sHeader.equals("Content-Length")) zLHE;
{ U&<Nhh
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); b!ea(D!:
break; |+0XO?,sZ
} dfoFs&CSKh
} rtM!|apr
else U|HF;L
break; wWNHZv&
} ]{<`W5b/
} T)NnWEB
catch(IOException e){e.printStackTrace ();} -n`igC
catch(Exception e){e.printStackTrace ();} /Xds+V^Z
B "z`X!\
\dz@hJl:
Utility.log(nFileLength); *Tt*\ O
o?$B<Cb"
"""gV)Y
return nFileLength; VYZkHjj)2i
} -OS&(7
G}&{]w@
JM@}+pX
//保存下载信息（文件指针位置） !L#>wlX)
private void write_nPos() NZyGC Vh@
{ Hi 1@
try{ 07_ym\N
output = new DataOutputStream(new FileOutputStream(tmpFile)); hF!t{ Lf3
output.writeInt(nStartPos.length); %dMP}k/
for(int i=0;i<nStartPos.length;i++) c_fx,; ;
{ v{}i`|~J
// output.writeLong(nPos); +hIStA
output.writeLong(fileSplitterFetch.nStartPos); m"<Sb,"x!
output.writeLong(fileSplitterFetch.nEndPos); 9;^r
} UtF8T6PKdW
output.close(); na&?Cw
} -];/*nl
catch(IOException e){e.printStackTrace ();} Dg$Z5`%k8
catch(Exception e){e.printStackTrace ();} ?Sq?f?
} DB'd9<
d_j% ,1-#
1N_Gk&
//读取保存的下载信息（文件指针位置） )5}=^aqd
private void read_nPos() G $TLWfm
{ /R@,c B=
try{ S0\;FmLIc
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); UvSvgDMl
int nCount = input.readInt(); v>FsP$p4yE
nStartPos = new long[nCount]; )x/Spb
nEndPos = new long[nCount]; HWJ(O/N
for(int i=0;i<nStartPos.length;i++) ,m-z D
{ CfguL@tR.
nStartPos = input.readLong(); NW'rqgG
nEndPos = input.readLong(); 6q[|U_3I@
} L7*,v5
input.close(); v`"z
} +rw?k/
catch(IOException e){e.printStackTrace ();} qn VxP&
catch(Exception e){e.printStackTrace ();} .Vm!Ng )j
} `.dX@<
P8N`t&r"7
TBN0uk
private void processErrorCode(int nErrorCode) jP?YV
{ 7~@9=e8G
System.err.println("Error Code : " + nErrorCode); CbmT aEaP
} B? $9M9
~s@PP'!
=IQ+9Fl2
//停止文件下载 }Ut*Y*
public void siteStop() B{UL(6\B
{ [?3]+xr:
bStop = true; t$NK{Mw5_
for(int i=0;i<nStartPos.length;i++) "P)f,n
fileSplitterFetch.splitterStop(); EZy:_xjZ
S]E1+,-*
_MF:?p,l
} J<g$hk
} &cDLSnR
//负责部分文件的抓取 dWK; h
**FileSplitterFetch.java ~=$0=)c
*/ ;D}8acQ
package NetFox; Y$3 &?LA
toDv~v
[{]/9E/&
import java.io.*; :fo.9J
import java.net.*; C|#GODA
SG:Fn8
0(!j]w"r3
public class FileSplitterFetch extends Thread { 4+rr3 $AY
dQX<X}
i2. +E&3v
String sURL; //File URL !i>&z?
long nStartPos; //File Snippet Start Position $AGW8"
long nEndPos; //File Snippet End Position ^|u7+b'|t
int nThreadID; //Thread's ID 'R'P^
boolean bDownOver = false; //Downing is over Y nD_:ZK
boolean bStop = false; //Stop identical IUB#Vdx
FileAccessI fileAccessI = null; //File Access interface xF:}a:c@H
]q#w97BxiJ
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException L#t^:%
{ YJBlF2uD
this.sURL = sURL; v[k;R
this.nStartPos = nStart; R,]J~TfPK
this.nEndPos = nEnd; $KSdNFtM)A
nThreadID = id; R^v-%mG9
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qDG{hvl[1r
} EESGU(
g8=j{]~C
]2:w?+T
public void run() #6fQ$x(F#j
{ "!-
while(nStartPos < nEndPos && !bStop) Z2Q'9C},m
{ {RG4m{#9
C?xah?Sk
0m3:!#\
try{ uPe&i5YR
URL url = new URL(sURL); Ox| ?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); BM~>=emc
httpConnection.setRequestProperty("User-Agent","NetFox"); A_8UPGh8
String sProperty = "bytes="+nStartPos+"-"; /Bt+Ov3k
httpConnection.setRequestProperty("RANGE",sProperty); Z<P?P`
Utility.log(sProperty); ,@\$PyJ
~J~@mE2ks
e8Ul^]
InputStream input = httpConnection.getInputStream(); y cT@D/
//logResponseHead(httpConnection); `_MRf[Z}
Rcn6puZt
=3~5I&
byte[] b = new byte[1024]; "b~-`ni
int nRead; G+_Q7-o&d6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jDO"?@+
{ [Re.sX}$Y
nStartPos += fileAccessI.write(b,0,nRead); 4](jV}Hg
//if(nThreadID == 1) =c-Y >
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); .RazjXAY
} 8I>'xf
o4.?m6d
=<BPoGs5
Utility.log("Thread " + nThreadID + " is over!"); Th'B5:`
bDownOver = true; dmB _`R
//nPos = fileAccessI.write (b,0,nRead); nB|m!fi<
} &06pUp iS
catch(Exception e){e.printStackTrace ();} &.v|yG]&
} d`w3I`P1
} p2=+cS"HC
PHxU6UPqy
["u:_2!4P
//打印回应的头信息 Jan~Rran
public void logResponseHead(HttpURLConnection con) +|w%}/N
{ 2Wx~+@1y
for(int i=1;;i++) x/d(" Bb
{ srGF=1_
String header=con.getHeaderFieldKey(i); 2ophh/]
if(header!=null) %a=^T?8
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ev4f9Fhu
Utility.log(header+" : "+con.getHeaderField(header)); (teK0s;t5k
else (i.7\$4
break; "9v4'"
} .4cVX|T
} qS!U1R?s
9F"^MzZ
SZVAf|]Yg
public void splitterStop() xbNL <3"a
{ s?yl4\]Muf
bStop = true; c}G\F$
} F&_b[xso7
lc(}[Z/|V
(7*((
} ~(x"Y\PEu
0% zy 6{
3+WmM4|
/* 4XNdsb
**FileAccess.java \LYNrL~?J
*//文件访问(定位，写) ..fbRt
package NetFox; o:c:hSV
import java.io.*; i`7(5L~`
QB<~+dW
o^3X5})sv
public class FileAccessI implements Serializable{ (7A-cC
M`49ydh&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 *%n(t+'q
RandomAccessFile oSavedFile; hkDew0k
long nPos; J,D^fVIw
2I>`{#fV
^u+#x2$Mg
public FileAccessI() throws IOException .H}#,pQ}l
{ Oq[YbQ'GE
this("",0); h#}'9oA
} q^eLbivVE
560`R>
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public FileAccessI(String sName,long nPos) throws IOException 1'!%$D
{ 0gsRBy
oSavedFile = new RandomAccessFile(sName,"rw"); #A 7|=E
this.nPos = nPos; ld[BiP`B2V
oSavedFile.seek(nPos); TlCGP)VSj
} :NynNu'
4G'-"u^g
@y/!`Ziw
public synchronized int write(byte[] b,int nStart,int nLen) H+5S )r
{ a49t/
int n = -1; rCd*'Qg
try{ #b@ sV$
oSavedFile.write(b,nStart,nLen); IqCh4y3
n = nLen; M~g{}_0Z
} Wrf+5 ;,,
catch(IOException e) Y'Yu1mH)
{ Q#lFt,.y
e.printStackTrace (); qoSZ+ khS$
} l}~9xa}:D|
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+R',$YzD
return n; Qov*xRO6
} "h:#'y$V
;umbld0
o('6,D
} Tbj}04;I
@7J;}9E
d0YQLh
/* J@qwz[d i
**SiteInfoBean.java wPvYnhr|G-
*/ ,[[Xo;q
package NetFox; LY2QKjgP
xiO10:L4
#ds@!u+&
public class SiteInfoBean { w"Y'I$
NdB:2P
?:3rVfO
private String sSiteURL; //Site's URL jZ0/@zOf
private String sFilePath; //Saved File's Path GpCjoNcW{
private String sFileName; //Saved File's Name {2LG$x-N%
private int nSplitter; //Count of Splited Downloading File >NZJ-:t
.xe+cK
$AHdjQ[;6-
public SiteInfoBean() Bp/25jy
{//nSplitter的缺省值为5 $s,(-C
//default value of nSplitter is 5 yGC3B00Z
this("","","",5); ztC>*SX
} yc0_7Im?
_.xicov
Muok">#3.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }LryRcrD-n
{ -*;JUSGh
sSiteURL= sURL; V82hk0*j
sFilePath = sPath; +THK Jn!>
sFileName = sName; #0c;2}D
this.nSplitter = nSpiltter; d_ji ..T
<+: PTG/('
LzD,]{CC5
} fz<GPw
Wux[h8G
0A F}wz>
public String getSSiteURL() LUEZqIf
{ /|8/C40aY
return sSiteURL; (f
} Ie/dMB=t
s ?|Hw|j
2{4f>,][
public void setSSiteURL(String value) lMe+.P|
{ O|*-J
sSiteURL = value; 0lS=-am
} `{xKU8j^
n7L|XkaQ
->2m/d4a
public String getSFilePath() 9/dADJe0b
{ =}2k+v-B
return sFilePath; d*l2x[8}g-
} m[tsG=XBN
Rln% Y
Y/y`c-VO
public void setSFilePath(String value) URj2 evYW
{ &S8,-~U
sFilePath = value; Gq{);fq
} 9z7rv,
b ; U
X;CRy,
public String getSFileName() 63c\1]YB.
{ =*KY)X
return sFileName; ^a=V.
} Jn"ya^~
t_id/
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public void setSFileName(String value) *`V r P
{ 6`Diz_(
sFileName = value; 4f'!,Q ;
} S.!K
t]8nRZ1
=jvL2ps<
public int getNSplitter() YB376/
{ WMnxN34
return nSplitter; qEfg-`*M
} t4+bRmS`_
4VHX4A}CgA
Ys8D|HIk
public void setNSplitter(int nCount) TbgIr
{ 4tz@?TCb
nSplitter = nCount; ^tI4FQ>Y
} x$.0:jP/s
} 9 !V,++j
/}nq?Vf
=h[;'v{
/* /~pB_l
**Utility.java 'SKq<X%R;
*/ jRhRw;
package NetFox; `: 9n ]xP
! l"*DR
cpM]APF-
public class Utility { 5EL&?\e
3 ]w a8|
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public Utility() CmdPa!4)
{ ]s`cn}d
m.c2y6<=
I36ClOG
} F **/T
@^nE^;
//线程睡眠 2tZ\/6G<
public static void sleep(int nSecond) ja^
{ wN:vI(C
try{ tLM/STb6
Thread.sleep(nSecond); fDwqu.K
} 9XX:_9|I
catch(Exception e) pXK-,7-
{ ,$"T/yYer
e.printStackTrace (); ;9hS_%ldX4
} >z k6{kC
} fT5vO.a
:xC1Ka%~
//日志 'S6JpWG1
public static void log(String sMsg) ,{BF`5bn|
{ wSG!.Ejc7
System.err.println(sMsg); G<`6S5J>hr
} r_pZK(G%
2E@g#:3
o^+g2;Ro
public static void log(int sMsg) T)MZ`dM
{ 5wbR}`8
System.err.println(sMsg); 7|X.E
} v[<;z(7Qk
} =qS\+
X9o6} %Y
HA~BXxa/
/* :@^T^
**TestMethod.java DxxY<OkN
*/ `$ZBIe/u
package NetFox; OVEQ^\Q5D
#%.fsJNA$
c='uyx
public class TestMethod { :nxBM#:xu
=|IY[2^
D()tP
public TestMethod() R'h.lX
{ ///xx/weblogic60b2_win.exe B0m2SUC,H
try{ +}Qq#^:_\
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); $q0i=l&$&
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1a'0cSH
SiteFileFetch fileFetch = new SiteFileFetch(bean); 9zlhJ7i
fileFetch.start(); =S|dzgS/
} 5wa!pR\c
catch(Exception e){e.printStackTrace ();} (gF{S*`
>?r8D48`
U2*kuP+n
} !^qpV7./l
>"pHk@AWK
E/3<8cV
public static void main(String[] args) #>O+!IH
{ AO]1`b:
new TestMethod(); tWITr
} ejlau#8"
} xQ>T.nP}1
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