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)); Ir]b.6B
} Y\j &84
for(int i=0;i<nEndPos.length-1;i++) /0(4wZe~?
{ \ 0:ITz
nEndPos = nStartPos[i+1]; AjZT- Q0L
} &qo'ge8p
nEndPos[nEndPos.length-1] = nFileLength; 0V1kZ.
} o]jo R3
} uz*C`T0:rj
t[3Upe%
+[*UC"
//启动子线程 S-v9z:M3
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; \Ud2]^D=
for(int i=0;i<nStartPos.length;i++) R/P.m~?
{ 8fdOV&&D~i
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 2Y$==j
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), S:DB%V3
nStartPos,nEndPos,i); 0`OqD d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4}8Xoywi1
fileSplitterFetch.start(); @UvjJ
} =lVfrna
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1P6~IZVN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Wmp\J3
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1AhL-Lj
nEndPos = " + nFileLength); J@1(2%)|Z
// fileSplitterFetch[nPos.length-1].start(); 4,)=r3;&!
y 5=J6a2.
!rrjA$P<v
//等待子线程结束 !WDdq_n*v
//int count = 0; CIV6Qe"<
//是否结束while循环 K5k,47"
boolean breakWhile = false; ukri7 n*
@^`-VF
/ZD/!YD&R
while(!bStop) ay4|N!ExO
{ ^B5Hjf9
write_nPos(); QAX+oy
Utility.sleep(500); 1)k))w9
breakWhile = true; uE/qraA
g|2D(J
#&DJ3(T
for(int i=0;i<nStartPos.length;i++) 6W3}6p
{ .%D] z{''
if(!fileSplitterFetch.bDownOver) FSH6C2
{ `L:wx5?
breakWhile = false; f!1KGP
break; u,&Z5S
} a3p|>M6E
} `.><$F
if(breakWhile) p%j@2U
break; LV9\
tMupX-V
}_u)3X.O
//count++; R|tjvp-[}
//if(count>4) ;m;wSp
// siteStop(); 'd/A+W
} r Cmqq/hZ
.o fYFK
Z^#7&Pv0
System.err.println("文件下载结束！"); <$ '#@jW
} b}[{'
catch(Exception e){e.printStackTrace ();} F7=a|g
} 3`-[95w
t$s)S>
oq;}q
//获得文件长度 tXfB.[U
public long getFileSize() Qza[~6
{ 8B\,*JGY2
int nFileLength = -1; 3):7mE(
try{ qB"y'UW8
URL url = new URL(siteInfoBean.getSSiteURL()); i"_JF-IbN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); r\L:JTZ$
httpConnection.setRequestProperty("User-Agent","NetFox"); GVFD_;j'
bx`(d@
W*VQ"CW{^]
int responseCode=httpConnection.getResponseCode(); >N44&W
if(responseCode>=400) ? BBDk
{ 8vnU!r
processErrorCode(responseCode); VRMlr.T+
return -2; //-2 represent access is error WqwD"WX+w
} M}us^t*
qOkw6jfluh
.8g&V|
String sHeader; F5)Ta?3|"<
JCE364$$"
,{YC|uB
for(int i=1;;i++) P`RM"'Om
{ +]UPY5:F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); A.y"R)G
//Utility.log(in.readLine()); 7!Fu.Ps >
sHeader=httpConnection.getHeaderFieldKey(i); v82@']IN
if(sHeader!=null) OhIUm4=|$
{ }p."7(
if(sHeader.equals("Content-Length")) 3",6 E(
{ ISOPKZ#F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %K?~$;Z.
break; u;y1leG
} 9KCnitU
} {9Y@?
else ]+,Z()
break; 5tQffo8t
} zoO>N'b3)
} u!;kBs
catch(IOException e){e.printStackTrace ();} 5>$*#0%"}
catch(Exception e){e.printStackTrace ();} XIf,#9
$D8KEkW
}|Cw]GW
Utility.log(nFileLength); &>sG xK
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4dl?US[-
return nFileLength; h&[!CtPm
} )V~<8/)
DR^mT$
FL0[V,
//保存下载信息（文件指针位置） *}3~8fu{
private void write_nPos() us$~6
{ 7;c{lQOj}
try{ &\K,kS[.r
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]+ug:E{7
output.writeInt(nStartPos.length); F;`es%8
for(int i=0;i<nStartPos.length;i++) trM8p
{ u{exQ[,E
// output.writeLong(nPos); hnH:G`[F
output.writeLong(fileSplitterFetch.nStartPos); hg=\L5R
output.writeLong(fileSplitterFetch.nEndPos); _d)w, ;m#
} O^|,Cbon6
output.close(); C+O`3wPZp
} pcm|
catch(IOException e){e.printStackTrace ();} !0E$9Xon
catch(Exception e){e.printStackTrace ();} 4Uz6*IQNl
} Zb8i[1P
0+M1,?+GfF
EGU?54
//读取保存的下载信息（文件指针位置） JA())0a
private void read_nPos() ?=f\oH$
{ \fh.D/@
try{ ]TqcV8Q~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); h.=YAcR0D
int nCount = input.readInt(); %%klR{
nStartPos = new long[nCount]; ;/>~|@
nEndPos = new long[nCount]; G2rxr
for(int i=0;i<nStartPos.length;i++) AaKILIIQZ
{ )` '
nStartPos = input.readLong(); EtN"K-X
nEndPos = input.readLong(); LBw,tP
} v]Pw]m5=U
input.close(); }evc]?1(
} Sr%~ 5Q[W
catch(IOException e){e.printStackTrace ();} Ow+7o@$"/
catch(Exception e){e.printStackTrace ();} &UQKZ.
} Pbd#Fu;
CM8WI~
i8u9~F
private void processErrorCode(int nErrorCode) R+rHa#M_
{ l AE$HP'o
System.err.println("Error Code : " + nErrorCode); *slZ17xg
} 4hZ-^AL"(
:IbrV@gN{@
tE<L4;t
//停止文件下载 _/P"ulNb
public void siteStop() ^J\)cw
{ xLq+njH E
bStop = true; {Yv |C)O
for(int i=0;i<nStartPos.length;i++) cidS/OH
fileSplitterFetch.splitterStop(); -&@[]/
(|h<{ -L
CA[k$Sw*
} q{n~s=
} ojtcKw
//负责部分文件的抓取 ?AYI
**FileSplitterFetch.java k:`^KtBMl
*/ $aG]V-M>
package NetFox; |`_TVzA
z[IG+2
K,+`td#
import java.io.*; K#+TCZ,
import java.net.*; S3btx9y{
LP#CA^*S
8I NVn'G
public class FileSplitterFetch extends Thread { "x3_cA~
[Z~>7ayF+)
^EZ)NG=e5
String sURL; //File URL S7~yRIjB
long nStartPos; //File Snippet Start Position E(8O3*=
long nEndPos; //File Snippet End Position =]U[
int nThreadID; //Thread's ID V4/eGh_T
boolean bDownOver = false; //Downing is over ,Sghi&Ky
boolean bStop = false; //Stop identical %Xkynso~
FileAccessI fileAccessI = null; //File Access interface |'Ve75 W6u
FSc730rM
>L[,.}(9
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException QF!K$?EU[
{ *l_1T4]S
this.sURL = sURL; zVkHDT[
this.nStartPos = nStart; C Hyb{:<
this.nEndPos = nEnd; bZ )3{
nThreadID = id; |I85]'K9a
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q35%t61Lc
} 0v+5&Jk
r$G;^
:,]%W $f=
public void run() BYNOgB1
{ h`&mW w
while(nStartPos < nEndPos && !bStop) 0`,a@Q4
{ pr@8PD2%
*N< 22w
o6Vc}jRH
try{ )<-kS
URL url = new URL(sURL); 'Kp|\Tr
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )Ky0q-W
httpConnection.setRequestProperty("User-Agent","NetFox"); tv\P$|LV`8
String sProperty = "bytes="+nStartPos+"-"; LW ntZ.
httpConnection.setRequestProperty("RANGE",sProperty); ~cU,3g
Utility.log(sProperty); 3Mr)oM<Q
O#cXvv]Z*
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InputStream input = httpConnection.getInputStream(); [4PG_k[uTJ
//logResponseHead(httpConnection); H)t8d_^|j
vA(3H/)-
&$< S1
byte[] b = new byte[1024]; mZMLDs:
int nRead; k3^S^Bv\
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 7QQ1oPV
{ ~`8`kk8
nStartPos += fileAccessI.write(b,0,nRead); ,i,f1XJ|
//if(nThreadID == 1) /of,4aaK7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); X(g<rz1J]
} _U#ue
?6tuo:gP
T"dWrtO
Utility.log("Thread " + nThreadID + " is over!"); )]X_')K
bDownOver = true; fvN2]@:
//nPos = fileAccessI.write (b,0,nRead); is#?O5:2
} Kax85)9u
catch(Exception e){e.printStackTrace ();} %8hhk]m\b>
} wU?2aXY
} RHVMlMX
vseuk@>
'DRyOJnr
//打印回应的头信息 &ATjDbW*(
public void logResponseHead(HttpURLConnection con) }g>&l.2X
{ ]>*Z 1g;
for(int i=1;;i++) FkKx~I:
{ V&)-u(s_S/
String header=con.getHeaderFieldKey(i); *hFT,1WE=+
if(header!=null) vF1]L]z:?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !mq+Oz~
Utility.log(header+" : "+con.getHeaderField(header)); 7tit>dJ
else wQ4/eQ*
break; )jCAfdnCs
} `6Y'H2WJ?
} "m/0>UU0
9dSKlB5J
+}X@{DB
public void splitterStop() 80axsU^H0
{ M0"xDvQ
bStop = true; -zG/@.
} "mHSbG
pkBmAJb@
a?\ Au
} V4ayewVX
Gi ZyC
70*Y4'u}A
/* (MwB%g
**FileAccess.java OG!^:OY
*//文件访问(定位，写) mA3C)V
package NetFox; S%g`X
import java.io.*; '0/t|V<
8[2^`g
;`s/|v
public class FileAccessI implements Serializable{ ze!7qeW
;]vE"Mx$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ix*n<lCoC
RandomAccessFile oSavedFile; dM#\h*:=
long nPos; o!\Vk~Vi&
V mKMj'
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public FileAccessI() throws IOException M(I 2M
{ g2w0#-
this("",0); b@z/6y!
} hPD2/M
&kYg >X
#RZW)Br
public FileAccessI(String sName,long nPos) throws IOException V\X.AGc
{ vYrqZie<
oSavedFile = new RandomAccessFile(sName,"rw"); mqw&SxU9
this.nPos = nPos; vezX/xD?
oSavedFile.seek(nPos); ^5j9WV
} oT%~)g
T+N%KRl
Ba6''?;G
public synchronized int write(byte[] b,int nStart,int nLen) ([tbFI}A
{ v#nYH?+~mJ
int n = -1; EcBSi995dj
try{ `NyvJt^<
oSavedFile.write(b,nStart,nLen); Lc0^I<Y
n = nLen; "P"~/<:)
} ?_}[@x
catch(IOException e) MXSPD#gN
{ gKn"e|A
e.printStackTrace (); "*XR'9~7
} L%U-MOS=
qL UbRp
=<n+AqJ%
return n; *siS4RX2
} |*i0h`a
GC~Tfrf=r
T>.*c6I b
} Abd&p N
!1w=_
P*)}ENY
/* Xr6UN{_-
**SiteInfoBean.java F{B__Kf
*/ WFsa8qv
package NetFox; NuLQkf)
28>gAz.#
FF)F%o+:w
public class SiteInfoBean { aj|I[65
W6 f*>
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private String sSiteURL; //Site's URL egK,e?~
private String sFilePath; //Saved File's Path aOA;"jR1
private String sFileName; //Saved File's Name d^!)',`
private int nSplitter; //Count of Splited Downloading File 89k9#i X
[8(e`6xePb
~4`LOROC
public SiteInfoBean() -*M/,O
{//nSplitter的缺省值为5 A +e ={-*
//default value of nSplitter is 5 K p~x
this("","","",5); p4*VE5[?_+
} o} YFDYi
|!aMj8i2
0[H'l",~
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Ky|dRbK,
{ @s b\0}
sSiteURL= sURL; VSL6tQp
sFilePath = sPath; G=!Gy.
sFileName = sName; 4b,N"w{v
this.nSplitter = nSpiltter; {%)bxk6
fnN"a Z
gp$oQh#37;
} wtu WzHrF
:1PT`:Y
$NWXn,Y'
public String getSSiteURL() N3!x7J7A
{ 7D@O:yO
return sSiteURL; >Ke4lO"
} :{E;*v_!v
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public void setSSiteURL(String value) -WWa`,:
{ R0B\| O0Uv
sSiteURL = value; 2E9Cp
} #tRLvOR:
xrFFmQ<_W
)}0(7z Yu
public String getSFilePath() cz~Fz;)2{N
{ J'G 6Z7
return sFilePath; GKTrf\"c
} t,gKN^P_
rn"'tvhm
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public void setSFilePath(String value) K@)Hm\*
{ EC<g7_0F
sFilePath = value; Gg]>S#^3
} $Y5R^Y
Fo|6 PoSo
jeFX?]Q
public String getSFileName() ^i&sQQ({
{ a^hDxeG
return sFileName; xX.fN7[
} Y6~/H
s5_[[:c=^
'vq-~y5^#
public void setSFileName(String value) Mj&q"G
{ j7IX"O%f\
sFileName = value; PHU#$LG
} bS=aFl#
u0(H!
$p#)xx7
public int getNSplitter() \dO9nwa?
{ 52 ?TLID
return nSplitter; 9lbe[w@
} /GCI`hx>"
%JF.m$-
(RW02%`jjy
public void setNSplitter(int nCount) iG()"^G
{ ~>2@55wElp
nSplitter = nCount; !C]0l
} TPEg>[
} }pxMO? h$
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`O4Ysk72x9
/* TUuw
**Utility.java q1Gc0{+)
*/ E%@,n9T~"
package NetFox; 7D PKKvQ
,Dd )=
6c>cq\~E
public class Utility { 96x$Xl;
| #Z+s-
sOQF_X(.x
public Utility() YC+}H33
{ cy T,tN
Eh/B[u7T[
`"`/_al^
} xF![3~~3[
7DQ{#Gf#G
//线程睡眠 Z.TYi~d/9D
public static void sleep(int nSecond) pxy=edd
{ JG\T2/b
try{ "|ZC2Zu<
Thread.sleep(nSecond); |+K3\b
} Qk2^p^ T6
catch(Exception e) +ExXhT
{ }QrBN:a$(
e.printStackTrace (); ~IrrX,mp:
} ElLDSo@WvR
} -]HPDN,OB
j:ze5FA+
//日志 s~(!m. R
public static void log(String sMsg) ntK#7(U'
{ 0wL-Ak#v
System.err.println(sMsg); 6^_:N1@
} T:k-`t0":N
/<ODP6Yy;
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public static void log(int sMsg) BSU%.tmI
{ 8ExEhBX8
System.err.println(sMsg); 3<">1] /,
} @)nxX))a
} =*<Cw?Gc
Xo^P=uf%
7:iTx;,v
/* _gDEIoBp
**TestMethod.java eb%`ox@&
*/ 5M6`\LyU
package NetFox; 9C9>V]
3Ov? kWFO
tgeX~.
public class TestMethod { !Q(xA,p
j8gw]V/B:
+$_.${uwV
public TestMethod() }e[;~g\&
{ ///xx/weblogic60b2_win.exe W\f u0^
try{ zb<YYJ]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); B'sgCU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); R)}ab{A
SiteFileFetch fileFetch = new SiteFileFetch(bean); pgNyLgN
fileFetch.start(); $646"1S
} +Wgp~$o4
catch(Exception e){e.printStackTrace ();} 21k^MZ
:g@H=W
,gYbi-E
} NHI(}Ea|]
Js{X33^Ju
KYe@2 6
public static void main(String[] args) 0_\@!#-sml
{ ?4QX;s7
new TestMethod(); m3Ma2jLWC
} !mX-g]4E
} 2GRL`.1
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