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)); @VKN6yHH
} o;{BI Q1
for(int i=0;i<nEndPos.length-1;i++) {} Zqaf
{ .QM>^(o$Z
nEndPos = nStartPos[i+1]; `z6I][Uf
} "l-R|>6~
nEndPos[nEndPos.length-1] = nFileLength; <3[0A;W=1
} nW_cjYS%
} ]9$^=z%SE
)SWLX\b
}Gh95HwE
//启动子线程 JR4fJG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @@#h-k%k-
for(int i=0;i<nStartPos.length;i++) p2(Z(V7*
{ cFloaCz
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _ v3VUm#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), HV8=b"D"
nStartPos,nEndPos,i); Amj'$G|+hj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t/(rB}
fileSplitterFetch.start(); l !:kwF
} Ws:MbZyr
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C;XhnqWv+l
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); R b=q #
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", }\aJ%9X02
nEndPos = " + nFileLength); klx28/]
// fileSplitterFetch[nPos.length-1].start(); Isg\ fSK<j
%<^j=K= 0
#9p|aS\
//等待子线程结束 6l&,!fd
//int count = 0; 4*V[^mht
//是否结束while循环 o'|B|oZ
boolean breakWhile = false; ]q3.^F
:r}C&3
ugS
while(!bStop) @*-t.b2k
{ #,Cz+k*4
write_nPos(); P$*9Z@
Utility.sleep(500); :HkXsZ
breakWhile = true; !p{CsR8c
?OVje9
f}w_]l#[G
for(int i=0;i<nStartPos.length;i++) q:u,)6
{ +PKd </*]
if(!fileSplitterFetch.bDownOver) }mOo=)C!
{ 9i+`,r
breakWhile = false; eR:C?v
break; kxt/I<cs
} p;.M.
} t_jnp $1m
if(breakWhile) )F,z pGG
break; !uqp?L^;
dK>sHUu
C{OkbE"Vym
//count++; KRb'kW
//if(count>4) $) m$c5!
// siteStop(); #M@~8dAH}M
} 1C(sBU"
8T88
j%=X ps
System.err.println("文件下载结束！"); ^o4](l
} USZBk0$
catch(Exception e){e.printStackTrace ();} H:cAORLB
} UHR%0ae
P~s u]+
ZP'0=
//获得文件长度 $N\k*=
public long getFileSize() U'@ ![Fp
{ (#8B
int nFileLength = -1; &cwN&XBY
try{ -^q;e]+J
URL url = new URL(siteInfoBean.getSSiteURL()); izs=5
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); RoNE7|gF:
httpConnection.setRequestProperty("User-Agent","NetFox"); c2-oFLNP=
Ko0?c.l
_ Y7Um
int responseCode=httpConnection.getResponseCode(); !6,rN_a@Y
if(responseCode>=400) hDXaCift
{ s"R5'W\U
processErrorCode(responseCode); a(X V~o
return -2; //-2 represent access is error 2D/bMq
} &hih p"
'}IGV`c
NS-0-o|4#
String sHeader; )!~,xl^j{}
I51I(QF=
dh9@3. t
for(int i=1;;i++) ~tn$AtK
{ GL~ Wnt
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); uh`5:V
//Utility.log(in.readLine()); ,&y_^-|d
sHeader=httpConnection.getHeaderFieldKey(i); ESUO I
if(sHeader!=null) m_.9PZ
{ +\$c_9|C+
if(sHeader.equals("Content-Length")) A1r%cs
{ _]-8gr-T
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); wY ??#pS
break; f@[)*([
} Y>atJ
} RA?_j$
else Jg)( F|>o
break; 8!YQ9T[
} :,fT^izew
} (:F]@vT
catch(IOException e){e.printStackTrace ();} o")"^@Zhi
catch(Exception e){e.printStackTrace ();} ay|jq"a
&nwS7n1eb
zliMG=6
Utility.log(nFileLength); P_'{|M<?
bDudETl
&n6L;y-
return nFileLength; 'IFA>}e7W
} TspX7<6r
v_Df+
VrLp5?Bh
//保存下载信息（文件指针位置） LT>_Y`5>
private void write_nPos() A+GRTwj
{ O2?yI8|Jn
try{ <T;V9(66
output = new DataOutputStream(new FileOutputStream(tmpFile)); vq.o;q /
output.writeInt(nStartPos.length); mj'N)6ga
for(int i=0;i<nStartPos.length;i++) tzfyS#E
{ $MGKGWx@E
// output.writeLong(nPos); ]*'_a@h
output.writeLong(fileSplitterFetch.nStartPos); |d-x2M[
output.writeLong(fileSplitterFetch.nEndPos); uF1 4;
} Z,SV9 ~M
output.close(); oV;sd5'LG
} he/rt#
catch(IOException e){e.printStackTrace ();} ]kx<aQ^
catch(Exception e){e.printStackTrace ();} $]Ix(7@W
} J[r_ag
)/JVp>
jnbR}a=fJ
//读取保存的下载信息（文件指针位置） B~k{f}
private void read_nPos() ;dMr2y`6
{ X Db%-
try{ 7Ok-T10
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); G7|d$!%
int nCount = input.readInt(); SP<Sv8Okj
nStartPos = new long[nCount]; V6](_w!
nEndPos = new long[nCount]; jD"nEp-
for(int i=0;i<nStartPos.length;i++) F):kF_ho
{ <*z'sUh+}
nStartPos = input.readLong(); H)E,([
nEndPos = input.readLong(); "%+||IyW
} D</?|;J#/
input.close(); xu"-Uj1
} 0sKoNzE
catch(IOException e){e.printStackTrace ();} m<z?6VC
catch(Exception e){e.printStackTrace ();} Z.Z31yF:f
} Lg,ObVt!
.#Z'CZO|
[.Md_
private void processErrorCode(int nErrorCode) E&z^E2
{ a6ryyt 5
System.err.println("Error Code : " + nErrorCode); z1,#ma}.
} J Q*~le*
tj00xYY
+}(]7du
//停止文件下载 Gw-{`<CxE
public void siteStop() ~H?v L c;>
{ @XL49D12c
bStop = true; /Us+>vg!
for(int i=0;i<nStartPos.length;i++) >wb*kyO7(#
fileSplitterFetch.splitterStop(); QD^=;!
psx_gv,
d^$cx(2$D
} {Fyw<0 [@
} !@Vj&>mH$
//负责部分文件的抓取 u 1}dHMoX~
**FileSplitterFetch.java I Gb'ii=A
*/ bzZdj6>kX
package NetFox; X=6L-^o)
,g?M[(wtc
;UX9Em
import java.io.*; j+/EG^*/
import java.net.*; OEbZs-:
#3?"#),q
P&5vVA6K7
public class FileSplitterFetch extends Thread { F3Da-6T@
9S'\&mRl
HP3%CB
String sURL; //File URL n Zx^ej\
long nStartPos; //File Snippet Start Position C5Fq%y{$.
long nEndPos; //File Snippet End Position S*3$1BTl
int nThreadID; //Thread's ID MfLus40;n
boolean bDownOver = false; //Downing is over p"cY/2w:j
boolean bStop = false; //Stop identical {"|GV~
FileAccessI fileAccessI = null; //File Access interface (lit^v,9
:t+LuH g
5/m*Lc+r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException c No)LF
{ |?' gT"#
this.sURL = sURL; T~}g{q,tR
this.nStartPos = nStart; zn*i
this.nEndPos = nEnd; \4*i;a.kU
nThreadID = id; mn{R>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 F>@z&a}(
} ;%u)~3B$JK
1EV0Y]T1
Uf[Gs/!NV
public void run() &j{IG`Trl
{ }LZz"b<aw
while(nStartPos < nEndPos && !bStop) jz&=8
{ 6XVJ/qZ
DshRH>7s8
1b!5h
try{ e7U9"pk
URL url = new URL(sURL); _8z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9'p pb
httpConnection.setRequestProperty("User-Agent","NetFox"); \ $9n `
String sProperty = "bytes="+nStartPos+"-"; T5 BoOVgO
httpConnection.setRequestProperty("RANGE",sProperty); 1;MUemnx`
Utility.log(sProperty); 3e^'mT
+xtR`Y"
*YY:JLe
InputStream input = httpConnection.getInputStream(); &+t,fwlM
//logResponseHead(httpConnection); G;pxB,4s5
l4Y}<j\;
c=HL 6v<
byte[] b = new byte[1024]; ;H8A"$%n~
int nRead; M3dNG]3E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) r&ex<(I{
{ }mw31=2bD
nStartPos += fileAccessI.write(b,0,nRead); "ealYveu
//if(nThreadID == 1) f8 M=P.jz
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); mYzq[p_|j
} cB7=4:U
eq\{*r"DCK
C'}8
Utility.log("Thread " + nThreadID + " is over!"); GVp2|\-L
bDownOver = true; Ye_)~,{,p
//nPos = fileAccessI.write (b,0,nRead); P A9 ]L
} z|SLH<~
catch(Exception e){e.printStackTrace ();} b-+iL
} wLC|mByq
} 8a1G0HRQ
l$Y7CIH
dDy9yw%f?
//打印回应的头信息 CtA0W\9w5a
public void logResponseHead(HttpURLConnection con) kqA`d
{ {E`f(9r:
for(int i=1;;i++) p_QL{gn
{ S-:l 60.
String header=con.getHeaderFieldKey(i); @Tzh3,F2
if(header!=null) BfF$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); W%.Kr-[?`o
Utility.log(header+" : "+con.getHeaderField(header)); ]#[R^t
else ]pr;ME<M{
break; avk0pY(n
} F,`y_71<
} qGgT<Rd~1
*B`wQhB%
Wel-a< e
public void splitterStop() *A O/$K@Ma
{ 5o2;26c
bStop = true; r/fLm8+
} Ohnd:8E
eEQ 4L\d
$}7/mS@c
} #IyxH$
q!9SANTx
q?{wRBVVB
/* {cKKTDN
**FileAccess.java 5B@+$D[0?3
*//文件访问(定位，写) +dk}$w[g
package NetFox; 9#.nNv*z3
import java.io.*; izow=}
=\?KC)F*e
{(AYs*5
public class FileAccessI implements Serializable{ zN {'@B
c:4M|t=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Sim\+SL{#
RandomAccessFile oSavedFile; Q'&oSPXSDd
long nPos; DnP>ed"M!
X4lz?Y:*
NI\jGR.
public FileAccessI() throws IOException kc\^xq~
{ 4WZ:zr N
this("",0); :03w k)
} `\P#TBM
sME3s-
B_anO{3$4
public FileAccessI(String sName,long nPos) throws IOException ]i)m
{ 34Q l7LQp[
oSavedFile = new RandomAccessFile(sName,"rw"); gN Xg
this.nPos = nPos; OW\r }
oSavedFile.seek(nPos); %vDN{%h8
} <V#9a83JP
K 38e,O
htj:Z:C`
public synchronized int write(byte[] b,int nStart,int nLen) <T+)~&g$
{ hW6og)x
int n = -1; #HpF\{{v
try{ i<l_z&
oSavedFile.write(b,nStart,nLen); (;;%B=
n = nLen; k*d0ws#<l
} 9aFu51
catch(IOException e) Eq=~SO%
{ \wEHYz
e.printStackTrace (); P3UU~w+s
} L\)ssOuh
eme7y
'/%]B@!
return n; ?zGx]?1P1<
} ?55t0
7v3'JG1r-
y_boJ
} AI0YK"c?
ce@1#}*
82l$]W4
/* Y S/x;
**SiteInfoBean.java ;c p*]
*/ A?i ~*#wE
package NetFox; 4zyN>f|
h|qTMwPr
4&%0%
public class SiteInfoBean { V>D8l @
j5\z7
hOZ:r =%
private String sSiteURL; //Site's URL ;Z^\$v9?
private String sFilePath; //Saved File's Path C.qNBl*
private String sFileName; //Saved File's Name s^f7w
private int nSplitter; //Count of Splited Downloading File 2%4u/
rlxZ,]ul
Qw>~]d,Z
public SiteInfoBean() <@:RS$"i
{//nSplitter的缺省值为5 by07l5
//default value of nSplitter is 5 ]R%[cr
this("","","",5); pmda9V4
} ^UU@7cSi|G
KU$:p^0l;*
8XfhXm>~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) uuHg=8(
{ mok94XuK)
sSiteURL= sURL; X1DE
sFilePath = sPath; ^IQtXae6M
sFileName = sName; ^mH:8_=(.
this.nSplitter = nSpiltter; df\^uyD;
i~Qnw-^B
p1F{ v^
} l,fwF ua
>]{{5oOQ>
88x2Hf5I
public String getSSiteURL() 79&=MTM
{ osM[Xv
return sSiteURL; F\u]X
} ;t~Y>,
-HwqR Ys
/,d]`N!
public void setSSiteURL(String value) f;D(X/"f]
{ [_T6
sSiteURL = value; xs 1V?0
} .R^R32ln
u+lNcyp"MW
.(^%M 2:6
public String getSFilePath() 4Sz2 9\X
{ (N6=+dNY
return sFilePath; ilRPV'S^
} 8B?*?,n5
~%eZQgqA*
t/lQSUip
public void setSFilePath(String value) g es-nG-
{ ? KDg|d
sFilePath = value; g-pEt#
} :jAsm[
QVF561Yz
! FVD_8
public String getSFileName() Ip<~Y
{ ep6V2R
return sFileName; J``5;%TJp
} WN $KS"b6}
wwNkJ+
`z^50Vh|
public void setSFileName(String value) fh*7VuAc
{ :IO"' b
sFileName = value; _b`/QSL
} ki'<qa
>]HvXEdNZ|
%CZGV7JdA
public int getNSplitter() bzaweAH
{ _VB;fH$
return nSplitter; SmS6B5j\R
} -k }LW4
D;hJK-Y
%(S!/(LWW
public void setNSplitter(int nCount) ]5Q)mWF
{ tb>Q#QB&u
nSplitter = nCount; "!Nu A
} *Z+U}QhHD6
} </B:Zjn
- i{1h"
R|k!w]
/* /g1;`F(MS/
**Utility.java T4J WZ
*/ 9&HaEAme
package NetFox; L*P*^I^1
NA YwuE-`
<vzU}JA\
public class Utility { S^N{=*
|}: D_TX
ZftucD|ZY/
public Utility() Gx|/ Jq
{ 1lsg|iVz
Snq0OxS[v
,!^g8zO
} R0yp9icS
:4>LtfA
//线程睡眠 Qqd+=mgc
public static void sleep(int nSecond) QbYNL9%
{ EkOn Rm_hn
try{ ZC&~InN
Thread.sleep(nSecond); 2{G7ignv
} q#0yu"<
catch(Exception e) :io~{a#.2\
{ BO 3z$c1yU
e.printStackTrace (); ZV!*ZpTe~
} km}E&ao
} "-Uqv@
?aZ\Dg{
//日志 s ~i,R
public static void log(String sMsg) c-[IgX e
{ ?o d*"M
System.err.println(sMsg); OQ<NB7'n0A
} E;r~8^9)
MENrP5AL
U6M&7l8
public static void log(int sMsg) PR>%@-Vgj
{ <h~_7Dn
System.err.println(sMsg); 6oGF6C
} XOzZtt
} 1gH>B5`
%U$%x
o&E2ds3
/* o&HFlDZ5jO
**TestMethod.java \fC}l Ll
*/ }}v28"\TA
package NetFox; H.TPKdVX
YfH+kDT
Y.o-e)zX
public class TestMethod { 4!<[5+.
J]Qbg7|
jF%l\$)/
public TestMethod() v&u8Ks
{ ///xx/weblogic60b2_win.exe UyOoyyd.
try{ t-w4rXvF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); a~;`&Uj
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); CA ,0Fe3
SiteFileFetch fileFetch = new SiteFileFetch(bean); O0>^?dsL
fileFetch.start(); _qhYG1t
} V: ivnx*
catch(Exception e){e.printStackTrace ();} 24/ ^_Td
iLG~_Ob:
TWJ%? /d
} <7sGA{
SN|:{Am
54, (;
public static void main(String[] args) L-(.v*
{ T=->~@5
new TestMethod(); c*x5t"{
} W%cJ#R[o
} mw&)j R$&
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