http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); _rJSkZO
} Z_~DTO2Qg
for(int i=0;i<nEndPos.length-1;i++) 0i`Zy!
{ +5mkMZ
nEndPos = nStartPos[i+1]; CscJy0dB
} BmF>IQ`M?
nEndPos[nEndPos.length-1] = nFileLength; 1O7ss_E
} 2^M+s\p
} ^ED>{UiNI
jtr=8OiL
h1o+7
//启动子线程 "FIx^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ph{+uI
for(int i=0;i<nStartPos.length;i++) $rYu4^
{ 2`U&,,-Mf
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V\hct$ 7Vm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 13kb~'+&r
nStartPos,nEndPos,i); z))[Lg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 7uNI
fileSplitterFetch.start(); +`3ZH9
} -y*+G&
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (UT*T
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); w>Sz^_ h
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ( +hI
nEndPos = " + nFileLength); 8N_rJ)f
// fileSplitterFetch[nPos.length-1].start(); !`=?<Fl
6e|5qKr
$*-L8An?
//等待子线程结束 }0>/G?2Yp
//int count = 0; PW4Wn`u
//是否结束while循环 X}Z%@tL
boolean breakWhile = false; .Q)"F /
oA@^N4PD
mXaUWgO
while(!bStop) P`"DepeD
{ .WE0T|qDX
write_nPos(); 'B6H/d>
Utility.sleep(500); bQjHQ"G
breakWhile = true; 3*JybMo"
:/l
l'\b(3JF
for(int i=0;i<nStartPos.length;i++) }rZ=j6Z
{ :+!b8[?Z
if(!fileSplitterFetch.bDownOver) ;rL$z;}8
{ L-$g& -
breakWhile = false; 6 74X)hB
break; Qf]!K6eR
} rWqA)j*!
} m/nn}+*C
if(breakWhile) $?{zV$r1
break; CI'5JOqP
E/;YhFb[
\c}r6xOr
//count++; >C3 9`1
//if(count>4) [1CxMk~"[
// siteStop(); ;gV8f{X{Z
} 9E?>B3t^
L1i> %5:g
O8o18m8UH
System.err.println("文件下载结束！"); &W!@3O{~.
} 0O4mA&&!oK
catch(Exception e){e.printStackTrace ();} {HnOUc\4
} o]U==
7SZs/wWh%
z\ pT+9&
//获得文件长度 sTyGi1
public long getFileSize() mIodD)?{
{ ~vFo 0k(
int nFileLength = -1; tH(#nx8
try{ q%9oGYjvQ
URL url = new URL(siteInfoBean.getSSiteURL()); /WVMT]T6^,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V=~dgy~@
httpConnection.setRequestProperty("User-Agent","NetFox"); rzLlM
mJ7kOQ-.$
B=`!
int responseCode=httpConnection.getResponseCode(); mH .I!
if(responseCode>=400) +8I0.,'
{ a!]%@A6p
processErrorCode(responseCode); 7yl'!uz)9
return -2; //-2 represent access is error 0fU>L^P_?
} blv6
a@J:*W
e?WR={
String sHeader; u*`GIRfWT
(p!AX<=z
-<=<T@,
for(int i=1;;i++) tm?
{ 5{TF6
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ]S ,GHPEN
//Utility.log(in.readLine()); -NeF6
sHeader=httpConnection.getHeaderFieldKey(i); :Ej)AfS
if(sHeader!=null) b\Ub<pE
{ 1| DI'e[X
if(sHeader.equals("Content-Length")) # 95/,k
{ q%Pnx_RB
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \gpKQt0
break; |\t_I~de
} HfPeR8I%i
} "RA$Twhj
else O~VUViS6$
break; t:7jlD!d
} k$!&3Rh
} Rw`s O:eZ
catch(IOException e){e.printStackTrace ();} Rim}DfO/
catch(Exception e){e.printStackTrace ();} &YNhKm@"
ZT#G:a
_P:P5H8
Utility.log(nFileLength); *p^MAk9=
|t_2AV
B#yyO>0k]
return nFileLength; {r)M@@[
} qFk(UazN
is$d<Y&F
JnDR(s4(E
//保存下载信息（文件指针位置） add-]2`
private void write_nPos() CjGI}t
{ A )cb
try{ H<"j3qt
output = new DataOutputStream(new FileOutputStream(tmpFile)); _guY%2%yR
output.writeInt(nStartPos.length); (k~c]N)v
for(int i=0;i<nStartPos.length;i++) +6*I9R
{ t {}1f
// output.writeLong(nPos); w=$_',5#Z
output.writeLong(fileSplitterFetch.nStartPos); RI=B(0A
output.writeLong(fileSplitterFetch.nEndPos); qxx.f58H
} }f}&|Vap
output.close(); RP9||PFS~~
} |IvX7%*]~
catch(IOException e){e.printStackTrace ();} F/Xhm91^
catch(Exception e){e.printStackTrace ();} Zj;!7ZuT1
} p\K5B,
4dP_'0]9A:
9^tyjX2
//读取保存的下载信息（文件指针位置） tJP(eaqZ
private void read_nPos() n9^zAcUbAW
{ o%a$m9I
try{ 3'wBX
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); M*N8p]3Cq
int nCount = input.readInt(); )UJMmw\
nStartPos = new long[nCount]; D[mYrWHpn
nEndPos = new long[nCount]; mqL+W
for(int i=0;i<nStartPos.length;i++) <#-ERQw
{ )j]RFt
nStartPos = input.readLong(); g2I@j3
nEndPos = input.readLong(); :>k\uW
} ilP&ctn6+c
input.close(); sMx\WTyz
} "`k[4C
catch(IOException e){e.printStackTrace ();} .+<K-'&=
catch(Exception e){e.printStackTrace ();} {`LV{!
} f8lww)^,v
EA\~m*k
79v&6Io
private void processErrorCode(int nErrorCode) vuf|2!kh/
{ ^&}Y>O,
System.err.println("Error Code : " + nErrorCode); yT4|eHl
} VWi-)
:vjbuqN]
{~SR>I3sv
//停止文件下载 oaHBz_pg
public void siteStop() ~EBZlTN
{ 0U<9=[~q7@
bStop = true; uD"Voh|]=
for(int i=0;i<nStartPos.length;i++) So:89T
fileSplitterFetch.splitterStop(); !v-(O"a
#?9oA4Q
Jj!T7f*-GX
} T1E=<q4
} - M]C-$
//负责部分文件的抓取 9SPu 4i
**FileSplitterFetch.java |Bid(`t.
*/ 5>HI/QG
package NetFox; PJLA^eC7>
"7g: u-
qv:WC TAn
import java.io.*; Z+?j8(:n
import java.net.*; 2+enRR~
h5JXKR.1]c
C9h8d
public class FileSplitterFetch extends Thread { S(Pal/-"
z)26Ahm TV
o|+tRl
String sURL; //File URL xASjw?
long nStartPos; //File Snippet Start Position xiI!_0'
long nEndPos; //File Snippet End Position y!#1A?|k
int nThreadID; //Thread's ID Umqm5*P(
boolean bDownOver = false; //Downing is over a4wh-35/
boolean bStop = false; //Stop identical (n<xoV[e
FileAccessI fileAccessI = null; //File Access interface 46vz=# ,6L
<1y%ch;
UX?_IgJh<"
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Ul=`]@]]
{ Abl=Ev
this.sURL = sURL; B 5?(gb"
this.nStartPos = nStart; ]OVjq?
this.nEndPos = nEnd; &"BKue~q@p
nThreadID = id; ,FTF@h-Cs
fileAccessI = new FileAccessI(sName,nStartPos);//定位 8wBns)wy@
} |^1eL I
jkbz8.K
yoH6g?!O
public void run() 4avM:h
{ X#J[Nn>
while(nStartPos < nEndPos && !bStop) eRGip2^cq+
{ Bpgl U=Qr
,YoIn
Gqs8$[o
try{ SbB5J> >7J
URL url = new URL(sURL); cIgF]My*D@
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1G\ugLm
httpConnection.setRequestProperty("User-Agent","NetFox"); ~"-wSAm
String sProperty = "bytes="+nStartPos+"-"; sB6UlX;b:
httpConnection.setRequestProperty("RANGE",sProperty); qRU8uu
Utility.log(sProperty); {M=tw
a7+BAma<
<Z vG&
InputStream input = httpConnection.getInputStream(); =q._Qsj?fu
//logResponseHead(httpConnection); o5)U3U1|
kxKBI{L
'K0Y@y
byte[] b = new byte[1024]; `:8&m
int nRead; W>"i0p
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Nk7Q
{ k8h$#@^
nStartPos += fileAccessI.write(b,0,nRead); ?0%lB=qQ
//if(nThreadID == 1) O6`@'N>6P
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *P_TG"^{W
} <_NF
<'/+E4m
f[.]JC+,
Utility.log("Thread " + nThreadID + " is over!"); MZ{)`7acR\
bDownOver = true; z_zr3XR9
//nPos = fileAccessI.write (b,0,nRead); c<e$6:|xM
} y"7?]#$9/
catch(Exception e){e.printStackTrace ();} SO}Hc;Q1`
} bSmRo
} ?vZ&CB
oV*3Mec
0n1y$*I4
//打印回应的头信息 uy B ?-Y+
public void logResponseHead(HttpURLConnection con) sI~{it#
{ HMBxj($eR
for(int i=1;;i++) r+) A)a,
{ 6OVAsmE
String header=con.getHeaderFieldKey(i); $ @^n3ZQ4
if(header!=null) %DiZ&}^Ck
//responseHeaders.put(header,httpConnection.getHeaderField(header)); %N!Y}$y
Utility.log(header+" : "+con.getHeaderField(header)); bzZEwMc6
else /$B<+;L!#
break; vHao y
} 50CU|
} Chjth"
;X\!*Loe
NxNz(R $~
public void splitterStop() )2\6Fy0S
{ N 4Dyec\
bStop = true; u%&zY97/
} w;X-i.%`
nkvzv
byd[pnI$H
} GXsHc,
x5{ zGv.j
lT*Hj.
/* %GAEZH,2sG
**FileAccess.java n2$*Z6.G
*//文件访问(定位，写) S9mj/GpL3
package NetFox; e\/Lcng
import java.io.*; 6tP^_9njy
rNZN}g
3C.bzw^
public class FileAccessI implements Serializable{ P_w+p"@m
f4uK_{
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 K^9!Qp
RandomAccessFile oSavedFile; Vk[m$
long nPos; 3EAu#c@q"
Q~uj:A]n<
G:f]z;Xdp
public FileAccessI() throws IOException o-/Xa[yC
{ 9!PJLI=D
this("",0); l^&#fz
} V7 c7(G
2c}>}A4
MA"DP7e?v
public FileAccessI(String sName,long nPos) throws IOException M7En%sBp
{ 7Sr7a{
oSavedFile = new RandomAccessFile(sName,"rw"); w${=]h*2
this.nPos = nPos; Cvq2UNz(R
oSavedFile.seek(nPos); "M2HiV
} AOeptv^k3}
9QZ;F4 r
!x|Ok'izDL
public synchronized int write(byte[] b,int nStart,int nLen) *y7^4I-J
{ h@l5MH=|%
int n = -1; ]Y:|%rvVH
try{ Haiuf)a
oSavedFile.write(b,nStart,nLen); #m|AQr|
n = nLen; 6f0 WN
} NO"=\Zn6
catch(IOException e) HJM-;C](
{ ]*Zg(YA
e.printStackTrace (); jF{zcYU
} ,D>$N3;
jFnq{Lt
9V("K
return n; KI#),~nS
} <T<?7SE+
>OmY
e<>(c7bF
} ,+%$vV .g\
u9QvcD^'z
umK~K!i
/* uQ. m[y
**SiteInfoBean.java rs'~' Y
*/ r6QNs1f~.
package NetFox; #%Uk}5;-
MHk\y2`/;
X5'foFE'
public class SiteInfoBean { T/UhZ4(V
r( :"BQ
r@^h,
private String sSiteURL; //Site's URL mRFcZ.7
private String sFilePath; //Saved File's Path g&#.zJ[-
private String sFileName; //Saved File's Name I[G<aI!
private int nSplitter; //Count of Splited Downloading File D8qZh1w%A|
5&\Q0SX(~
#8QQZdC8`
public SiteInfoBean() :J5xO%WA(
{//nSplitter的缺省值为5 P$4G2>D8dg
//default value of nSplitter is 5 n;y<!L7
this("","","",5); v|"Nx42
} D`2Iy.|!
Mq8jPjL
NAlYfbp
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) D~G24k6b3
{ ?,O{,2}
sSiteURL= sURL; D*I%=);B_
sFilePath = sPath; 6m|j "m
sFileName = sName; la[xbv
this.nSplitter = nSpiltter; [0w@0?[
`c ^2
c4k3|=f
} b<~\IPY
f^Lw3|rq4
=i4Ds
public String getSSiteURL() z;x$tO
{ 1nye.i~
return sSiteURL; &ScADmZP^d
} oyiEOC
Jo1n>Mo-j
X~T"n<:a>
public void setSSiteURL(String value) Yw vXSA
{ C2<!.l
sSiteURL = value; cF7I
} m\)z& hv<r
D4?5%s
"}Of f
public String getSFilePath() CD;C z*c
{ KW]/u
return sFilePath; T&
} 51u8.%{4
!U/iY%NE
]g2Y/\)a
public void setSFilePath(String value) 9#IKb:9k
{ al.~[T-O+
sFilePath = value; y+hC !-
} S~.:B2=5K
nb9qVuAGU
^w/_hY!4/
public String getSFileName() lU`]yL
{ K!VIY|U
return sFileName; Po#;SG#Ee
} yZE"t[q#O
Z_.Eale^
:,X,!0pWRp
public void setSFileName(String value) &9g4/c-?$
{ k4FxdX
sFileName = value; `L/kwVl
} o}C|N)'
N{U``LV
Xt %;]1n
public int getNSplitter() e "5S;
{ \BOZhXfl'
return nSplitter; '8R5?9"
} wuSp+?{5k
u=JI 1
.H {
public void setNSplitter(int nCount) FIG3P))
{ Sp3?I2 o
nSplitter = nCount; Av:5v3%
} {{7%z4l
} %]S~PKx
0!!b(X(
(vMC.y5
/* 0wU8PZ Nj
**Utility.java $@<qaR{t\
*/ 8.3888
package NetFox; B#9rqC
Z[[ou?c
-]\cUQ0
public class Utility { (\}>+qS[
^|M\vO
TO7%TW{L
public Utility() !*_5 B'
{ z;yb;),
Hg\+:}k&9
&rj3UF@hb
} }YH@T]O}
=X6WK7^0
//线程睡眠 ?9hw]Q6r}
public static void sleep(int nSecond) 1:%HE*r
{ /R7qR#
try{ GP6-5Y"8
Thread.sleep(nSecond); }JyWy_Y
} m&(yx|a4+
catch(Exception e) `KBgVhS>
{ l ps 6lnh
e.printStackTrace (); {Hxvt~P
} O&YX V
} H. UwM
W|XTa
//日志 E#?*6/
public static void log(String sMsg) S(<r-bV<
{ %upnXRzw
System.err.println(sMsg); EkS7j>:
} q|,cMPS3
!m)P*Lw
>Q':+|K}
public static void log(int sMsg) jkw:h0hX
{ <+ 0cQq=2
System.err.println(sMsg); +Gv{Apd"
} ,b!!h]t
} =@$G3DM
EooQLZ
6yEYX'_
/* (%*CfR:>
**TestMethod.java 6) {jHnk)
*/ AW3\>WC
package NetFox; QB p`r#{I{
v).V&":
<\uz",e}
public class TestMethod { /Qi;'h]
3NRxf8
mNS7/I\
public TestMethod() o;bK 7D
{ ///xx/weblogic60b2_win.exe JQ|qg\[
try{ %HOMX{~}#
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k{_ Op/k}V
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ue8Cpn^M
SiteFileFetch fileFetch = new SiteFileFetch(bean); z*?-*6W
fileFetch.start(); $OOZ-+8
} vpR^G`/
catch(Exception e){e.printStackTrace ();} $t.i)wg +
^3B)i=
&<8Q/m]5
} H{Tt>k
|Y#KMi ~
{.c(Sw}Eo
public static void main(String[] args) *h6Lh]7
{ g}HB|$P7
new TestMethod(); #>~<rcE(
} ?Ne@OMc
} u%n6!Zx
点击下载更多相关资料