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)); y!#1A?|k
} Umqm5*P(
for(int i=0;i<nEndPos.length-1;i++) a4wh-35/
{ (n<xoV[e
nEndPos = nStartPos[i+1]; 46vz=# ,6L
} <1y%ch;
nEndPos[nEndPos.length-1] = nFileLength; UX?_IgJh<"
} 0V^?~ex
} Abl=Ev
B 5?(gb"
4&\m!s
//启动子线程 @*oi1_q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; TzOf&cs/r
for(int i=0;i<nStartPos.length;i++) tFGLqR%/
{ it.l;L_nW
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `27? f$,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Kl*##qw!
nStartPos,nEndPos,i); 9u9#&xx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); "x{S3v4Rb5
fileSplitterFetch.start(); GXAcyOV
} Uz0mSfBp
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G -;Yua2\
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]?kf;A@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a}wB7B;,g
nEndPos = " + nFileLength); 6ugBbP +^
// fileSplitterFetch[nPos.length-1].start(); K46\Rm_:B;
g$<@!
np~oF
//等待子线程结束 %spR7J\"/
//int count = 0; /XXW4_>
//是否结束while循环 \^+sgg{
boolean breakWhile = false; Rzb] mM
-Xj+7}4
*mYec~
while(!bStop) eq"~by[Uq
{ ^}WeBU
write_nPos(); @g{=f55
Utility.sleep(500); u+Li'Ug
breakWhile = true; C}Khh`8@5.
&t4j px
htaB!Q?V
for(int i=0;i<nStartPos.length;i++) k,r\^1h
{ ,xGlWH wrY
if(!fileSplitterFetch.bDownOver) P6X 4m(t
{ NE(6`Wq`
breakWhile = false; Cc=`:ED+
break; 9 Hm!B )Y
} Jzr(A^vwo
} U $+rlw}
if(breakWhile) l_8t[
break; O9opX\9
_h5@3>b3r
5!AzEB
//count++; 3&}wfK]X
//if(count>4) /_LUys/0
// siteStop(); 7c+u+Yet
} %3q@\:s
5SDHZ?h
j"c"sF\q
System.err.println("文件下载结束！"); r`" ?K]rI
} U'@_fg
catch(Exception e){e.printStackTrace ();} d=xweU<
} 7OT}V}iP
3i7n"8\$
Jx'p\*
//获得文件长度 A}$A~g5Ap
public long getFileSize() 8Uc#>Ae'_
{ s,0,w--=
int nFileLength = -1; e'u9 SpJ
try{ _$1W:!f4
URL url = new URL(siteInfoBean.getSSiteURL()); w{0UA6+
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;VvqKyUh7`
httpConnection.setRequestProperty("User-Agent","NetFox"); #j@Su )+
/9[nogP
eX}uZR
int responseCode=httpConnection.getResponseCode(); VDscZt)y8
if(responseCode>=400) T9u/|OP
{ B=9|g1e
processErrorCode(responseCode); E9|i:
return -2; //-2 represent access is error h8nJ$jg
} ?+51 B-
L!5%;!>.P
vK|dP3
String sHeader; >V NMQ
O10h(Wg
#.) qQ8*(
for(int i=1;;i++) iA=9Lel
{ Nn%{Ka
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Jln dypE
//Utility.log(in.readLine()); +`\C_i-
sHeader=httpConnection.getHeaderFieldKey(i); 8on2BC2
if(sHeader!=null) ]F-{)j
{ 7:;P>sF@
if(sHeader.equals("Content-Length")) Byon2|nf7
{ OrHnz981K
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); lB,.TK
break; xAsbP$J:
} Ww@Rewo
} zX(p\NU
else X1$0'usS
break; L7 qim.J
} AWGeK-^
} K47W7zR
catch(IOException e){e.printStackTrace ();} Io| 72W}rg
catch(Exception e){e.printStackTrace ();} LR}b^QU7
3TO$J
!x|Ok'izDL
Utility.log(nFileLength); *y7^4I-J
<0pBu7a
O7:JG[tR*
return nFileLength; Haiuf)a
} a&|aK+^8;
6EJ,czt(
Q;SMwCB0M
//保存下载信息（文件指针位置） OZ0q6"
private void write_nPos() h@/c76}f6p
{ oT.g@kf=H
try{ k_$w+Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); 2,'m]`;GNr
output.writeInt(nStartPos.length); l3-;z)SgH
for(int i=0;i<nStartPos.length;i++) k.?b2]@$
{ S_aml
// output.writeLong(nPos); 03[(dRK>=
output.writeLong(fileSplitterFetch.nStartPos); TDA+ rl
output.writeLong(fileSplitterFetch.nEndPos); :jgwp~l
} =p:D_b
output.close(); D.4=4"qMi
} #~ UG9@a
catch(IOException e){e.printStackTrace ();} p-r}zc9@
catch(Exception e){e.printStackTrace ();} b4i=eI8
} ^#p Su
*r$(lf
_=8x?fC:rl
//读取保存的下载信息（文件指针位置） wF[^?K '
private void read_nPos() EnZrnoGM
{ %YA=W=Yd
try{ @~xNax&^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4)i/B99k
int nCount = input.readInt(); /N]?>[<NW
nStartPos = new long[nCount]; b$H{|[
nEndPos = new long[nCount]; 1]m]b4]
for(int i=0;i<nStartPos.length;i++) K6{{\r
{ o%5^dX&[
nStartPos = input.readLong(); j;)U5X
nEndPos = input.readLong(); do C8!
} Fz~-m#Ts
input.close(); R"VmN2
} H5{d;L1[
catch(IOException e){e.printStackTrace ();} *EvnN:
catch(Exception e){e.printStackTrace ();} +QqYf1@F
} ) j_g*<
A9!%H6
7;+:J;xf66
private void processErrorCode(int nErrorCode) a3sXl+$D@
{ a>G|t5w
System.err.println("Error Code : " + nErrorCode); 6m|j "m
} Ft#d& I
[0w@0?[
`c ^2
//停止文件下载 c4k3|=f
public void siteStop() b<~\IPY
{ f^Lw3|rq4
bStop = true; b7p&EK"Hm
for(int i=0;i<nStartPos.length;i++) z;x$tO
fileSplitterFetch.splitterStop(); ]]J2#mN:n
ehPrxIyC
eI/9uR%
} JFIUD{>fp
} XL1v&'HLV
//负责部分文件的抓取 E?m(&O j
**FileSplitterFetch.java 5\A[ra
*/ {Ug?k<h7|
package NetFox; ^duNEu0*
_jQ"_Ff
4jfkCU
import java.io.*; m$Lq#R={Z
import java.net.*; rfpeX
m(L]R(t
LkD$\i
public class FileSplitterFetch extends Thread { OEnJ".&V
7aj|-gZ
TW8E^k7
String sURL; //File URL %XMwjBM
long nStartPos; //File Snippet Start Position |<t"O
long nEndPos; //File Snippet End Position s`B"qw
int nThreadID; //Thread's ID %qfql
boolean bDownOver = false; //Downing is over "qYPi
boolean bStop = false; //Stop identical l\vtz5L
FileAccessI fileAccessI = null; //File Access interface Py3Xvudv
a$y=+4L
,b%T[s7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >gtKyn]
{ T\55uQ
this.sURL = sURL; k4FxdX
this.nStartPos = nStart; u[$ \ az7
this.nEndPos = nEnd; !~u;CMR
nThreadID = id; e "5S;
fileAccessI = new FileAccessI(sName,nStartPos);//定位 wu"6Kyu
} (p08jR '5
wuSp+?{5k
u=JI 1
public void run() RcIGIt
{ FIG3P))
while(nStartPos < nEndPos && !bStop) s-!Bpr16o0
{ gJ6C&8tl
{{7%z4l
%]S~PKx
try{ 2It$ bz
URL url = new URL(sURL); (vMC.y5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wg\*FfQn
httpConnection.setRequestProperty("User-Agent","NetFox"); yJkERiJV
String sProperty = "bytes="+nStartPos+"-"; RsIR}.*
httpConnection.setRequestProperty("RANGE",sProperty); B#9rqC
Utility.log(sProperty); Z[[ou?c
cLj@+?/
(\}>+qS[
InputStream input = httpConnection.getInputStream(); ^|M\vO
//logResponseHead(httpConnection); TO7%TW{L
Yj99[ c#]
z;yb;),
byte[] b = new byte[1024]; 20h|e+3
int nRead; (=cR;\s<
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +`O8cHx
{ xs_l+/cZ
nStartPos += fileAccessI.write(b,0,nRead); zA4m !l*eM
//if(nThreadID == 1) `!rH0]vy
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); UE33e(Q<
} t2d_XQOK
/^v?Q9=Y
Ao~ZK[u
Utility.log("Thread " + nThreadID + " is over!"); o_>id^$>B
bDownOver = true; zY6{ OP!#
//nPos = fileAccessI.write (b,0,nRead); R{uq8NA- W
} 5|&8MGW-$
catch(Exception e){e.printStackTrace ();} WlVp|s{TYP
} P[6@1
} 6UOV,`:m+
*$mDu,'8
a=}JW]
//打印回应的头信息 3#o!K
public void logResponseHead(HttpURLConnection con) s\A"B#9r
{ Q|/uL`_ni
for(int i=1;;i++) 8q*MhH>6I
{ U9GmkXRix
String header=con.getHeaderFieldKey(i); eV$pza
if(header!=null) Ej\EuX
//responseHeaders.put(header,httpConnection.getHeaderField(header)); # ~SuL3
Utility.log(header+" : "+con.getHeaderField(header)); R?@F%J;tx
else *ILx-D5qr
break; h$7rEs
} oxT..=-
} h>V8YJ
iy_'D
0?59o!@h
public void splitterStop() A??(}F L
{ [!9dA.tF
bStop = true; +NL^/y<;
} {Wp+Y9c[
Cj^:8 ?%
Gu} `X23
} `|@#~
A;VjMfoB
&Ohm]g8{2
/* FRa@TN/Ic
**FileAccess.java P9h]Bu
*//文件访问(定位，写) rrBu6\D
package NetFox; :l<)p;\
import java.io.*; r_/=iYYJ
z<2!|
,Y 1&[
public class FileAccessI implements Serializable{ `QC
xE%1C6~C<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 q2v:lSFY
RandomAccessFile oSavedFile; + <AD
long nPos; 3Jt_=!qlo
\z>Re$:
q0|u vt"
public FileAccessI() throws IOException ;4XvlcGo
{ Bc%A aZ0x
this("",0); e45gjjts
} -WiOs;2~/
YNV!(>\GE
34S|[PXd
public FileAccessI(String sName,long nPos) throws IOException 7d&_5Tj:
{ u;1/.`NPB
oSavedFile = new RandomAccessFile(sName,"rw"); U^jxKBq^
this.nPos = nPos; Cw`8[)=}o
oSavedFile.seek(nPos); qFEGV+
} ~P&Brn"=Rs
D5]4(]k&
F\&Sn1>k
public synchronized int write(byte[] b,int nStart,int nLen) .Cv0Ze
{ S;a'@5
int n = -1; K"~Tk`[0Q
try{ _ 4:@+{
oSavedFile.write(b,nStart,nLen); QP/6N9/
n = nLen; [^wEKRt&
} fBCW/<Z
catch(IOException e) E({+2}=1
{ u6&<Bv
e.printStackTrace (); OU)~ 02|\
} gq9D#B
\~V ZY
-dX{ R_*
return n; |Z%I3-z_DS
} Xk#"rM< Y
@\-i3EhR
J6x#c`Y
} (!FUu
ftBbO8e
]3.Un,F
/* Cj~45)r
**SiteInfoBean.java |$[WnYP
*/ Q`$Q(/
package NetFox; LW?Zd=
LxqK@Q<B
,(aOTFQS
public class SiteInfoBean { DG_tmDT4
~ou1{NS
kOfq6[JC
private String sSiteURL; //Site's URL ?f1PQ
private String sFilePath; //Saved File's Path !eb}jL
private String sFileName; //Saved File's Name P'o:Vhm_H
private int nSplitter; //Count of Splited Downloading File cG|)z<Z
\BB(0Ah+t
M6(oJ*
public SiteInfoBean() +uR|0Jo8X
{//nSplitter的缺省值为5 Z4S0{:XY
//default value of nSplitter is 5 eIVCg-l}
this("","","",5); X8!=Xjl)
} 7%rSo^t,L
a'R)3:S
Q_}i8p'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cG%ttfq\
{ npcB+6
sSiteURL= sURL; uQy5t:!
sFilePath = sPath; %9.] bd|%F
sFileName = sName; KX*Hev'K
this.nSplitter = nSpiltter; $`q8-+{
a }6Fj&hj
KM$5ZbCF:
} ?VM#Nf\
Dd+ f,$
%(4G[R[
public String getSSiteURL() ~$g$31/
{ V\axOz!
return sSiteURL; .E!p
} }5n((7@X
r,p6J7/lfS
nquKeH
public void setSSiteURL(String value) *SkUkqP9z
{ AF{k^^|H
sSiteURL = value; K`.wj8zGY
} 1](5wK-Z
F",]*>r
DJl06-s V
public String getSFilePath() `?{Hs+4P5
{ %qA +zPf
return sFilePath; ,e"A9ik#
} .y7&!a35
w, 0tY=h6
)"7hyW5
public void setSFilePath(String value) KZ ezA4
{ 3[Pa~]yS
sFilePath = value; YxMOr\B
} ]a% *$TF
T!6H5>zA
D .3Q0a6
public String getSFileName() DbSl}N;
{ k*bfq?E a
return sFileName; _]E ~ci}
} # k+Ggw
rl)(4ad=
]pLQ;7f7D
public void setSFileName(String value) cmDskQ:
{ E-,74B&H
sFileName = value; RL>Nl ow
} RVN"lDGA
2,Y8ML<
N"|^AF
public int getNSplitter() ^RkHdA
{ 1E Lzzn
return nSplitter; RMB?H)p+
} 9GS<d.#Nvc
Cna@3)_
gF%lwq
public void setNSplitter(int nCount) L1u
{ ,hK0F3?H>
nSplitter = nCount; lo:]r.lX{
} :oF\?e
} yWIM,2x}
P,RCbPC4
g#ZR,q
/* zypZ3g{vz
**Utility.java gf+Kr02~
*/ *IzcW6 [9
package NetFox; ^SCZ
Df;FOTTi%
HzB&+c?Z
public class Utility { 76[aOC2Ad
/_rAy
dQ^>,(
public Utility() @f0~a
{ M;W{A)0i1
9\*xK%T+
CogLo&.
} =mCUuY#
\s;]Tg
//线程睡眠 y]=v+Q*+
public static void sleep(int nSecond) zW%-Z6%D
{ !mpRLBH
try{ D8_m_M|P
Thread.sleep(nSecond); 'j$iSW&
} ?n/:1LN,
catch(Exception e) h 88iZK
{ f(DGC2R <
e.printStackTrace (); A<iF37.
} e =& abu
} ld94ek
yY*OAC
//日志 D@qq=M
public static void log(String sMsg) ]M{SM`Ya
{ }Evyfc#D
System.err.println(sMsg); fl~k')s
} V~5vVY_HG&
))!Z2PfD
%Ua*}C
public static void log(int sMsg) D`e!CprF
{ Kv+E"2d
System.err.println(sMsg); Z!6\KV]
} }"fP,:n"KN
} $c0SWz
mT@UQCG
@Th.=
/* '2zo
**TestMethod.java dk({J
*/ t=S94^g
package NetFox; <PW*vo9v
FqsG#6|x
3z: rUhA
public class TestMethod { qYIBP?`g
EBw}/y{Kt
)aquf<u@
public TestMethod() u4$d#0sA
{ ///xx/weblogic60b2_win.exe dT,X8 "
try{ H1|X0a(j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); KBzEEvx/$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 6luCi$bL
SiteFileFetch fileFetch = new SiteFileFetch(bean); )QaJYC^+
fileFetch.start(); m*P~X*St
} 9R>A,x(
catch(Exception e){e.printStackTrace ();} :<ujk
\UJ:PW$7
o&*1Mx<+
} N&S:=x:$S
;eG%#=>
EPI mh
public static void main(String[] args) xQ1&j,R]
{ @)VJ,Ql$Y
new TestMethod(); O:r<es1
} 'n4zFj+S
} DXKk1u?Tq
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