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)); JmeE}:5lpj
} U5OFw+J
for(int i=0;i<nEndPos.length-1;i++) #M<YNuE#"
{ F'"-aB ~
nEndPos = nStartPos[i+1]; S;u.Ds&
} HCx0'|J
nEndPos[nEndPos.length-1] = nFileLength; 8Zy*#[-
} hgbf"J6V8
} \6bvk_
Igw2n{})w
^*+j7A.n
//启动子线程 EPA 2_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^/cqE[V~,
for(int i=0;i<nStartPos.length;i++) +p&zM3:9w
{ \T!,Z;zK
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), %zo 6A1Q;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [mj=m?j
nStartPos,nEndPos,i); cB_9@0r[S
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); J@QOF+&
fileSplitterFetch.start(); A'Z!l20_
} k2fJ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gvPHB+#A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); S(^YTb7
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Y]^*mc0fE
nEndPos = " + nFileLength); eA{A3.f"Hz
// fileSplitterFetch[nPos.length-1].start(); 72/ bC
-8vGvI>
'T(Q
//等待子线程结束 |onLJY7)
//int count = 0; {NcJL< ;tS
//是否结束while循环 VbTX;?
boolean breakWhile = false; |`pBI0Sjo
Dm$SW<!l|
/sn }Q-Zy2
while(!bStop) 5!pNo*QK
{ xAO\'#m
write_nPos(); }@/Ox
Utility.sleep(500); @' %XdH
breakWhile = true; epG]$T![
t,'J%)j
!VXy67
for(int i=0;i<nStartPos.length;i++) JG&E"j#q
{ & P%#
if(!fileSplitterFetch.bDownOver) AZ4:3}
{ DZ4gp
breakWhile = false; 9Y2.ob!$}
break; D=Nt0y
} oB>#P-V
} dcTZL$
if(breakWhile) #xq3)B
break; 2}bXX'Y
w`r%_o-I
g/WDAO?d
//count++; ZoYllk
//if(count>4) u~VXe
// siteStop(); MmU`i ,z
} qx9;"Ut
eD3\>Y.z
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System.err.println("文件下载结束！"); YMy**
} W#kyD)(F
catch(Exception e){e.printStackTrace ();} iQ1[60?)T
} VC_F Cz
I[gPW7&S@
WvoIh4]
//获得文件长度 9$qw&j[
public long getFileSize() 2yD ?f8P4
{ Vq/hk
int nFileLength = -1; 1|s`z
try{ 0v6Z4Ahpo
URL url = new URL(siteInfoBean.getSSiteURL()); $ %|b6Gr/&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;CoD5F!
httpConnection.setRequestProperty("User-Agent","NetFox"); T00sYoK
tUW^dGo.
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int responseCode=httpConnection.getResponseCode(); Fp"c {
if(responseCode>=400) 9b&;4Yq!f
{ b$pCp`/MT
processErrorCode(responseCode); lp5'-Jo
return -2; //-2 represent access is error k^cnNx
} O'xp"e,
Os]. IL$
:oYSvK7>
String sHeader; 3q@H8%jcw
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s jaaZx1
for(int i=1;;i++) <lU(9) L;&
{ t$p%UyVE
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); LaZ @4/z!
//Utility.log(in.readLine()); DHyQ:0q
sHeader=httpConnection.getHeaderFieldKey(i); T-lP=KF=
if(sHeader!=null) ;9-J=@KY4
{ BZKg:;9
if(sHeader.equals("Content-Length")) jq_4x[
{ jeO`45O
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 0"N4WH O
break; u-bgk(u
} +afkpvj8
} Sj*W|n\gj
else Q,tjODc6n
break; #,FXc~V
} #Aj#C>
} `K[r5;QFKf
catch(IOException e){e.printStackTrace ();} ^5>W`vwp
catch(Exception e){e.printStackTrace ();} qI tbY%
R%t|R79I
iAPGP-<6
Utility.log(nFileLength); \{Je!#
Lm.N {NV'
9x(t"VPuS
return nFileLength; &|Rww\oJ
} 7fd,I%v
"jq6FT)O
o4j!:CI
//保存下载信息（文件指针位置） L$ ^ew0C
private void write_nPos() !c0x^,iE
{ .<YfnW5/K
try{ sYSq>M
output = new DataOutputStream(new FileOutputStream(tmpFile)); gdh|X[d
output.writeInt(nStartPos.length); muBl~6_mb2
for(int i=0;i<nStartPos.length;i++) 9KT85t1#
{ )(1tDQ`L>
// output.writeLong(nPos); n$>_2v
output.writeLong(fileSplitterFetch.nStartPos); vS:=%@c>ta
output.writeLong(fileSplitterFetch.nEndPos); R!\._m?\h
} kFT*So`'
output.close(); Gg:W%&#
} _g D9oK
catch(IOException e){e.printStackTrace ();} 31M'71s
catch(Exception e){e.printStackTrace ();} $bBUL C
} CG J_k?h
M:d|M|'
mZ3Z8q}%P
//读取保存的下载信息（文件指针位置） &Ot9"Aq:
private void read_nPos() x[BA <UNO
{ C nD3%%
try{ V=PK)FJ
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); OU^I/TU
int nCount = input.readInt(); &sXk!!85:
nStartPos = new long[nCount]; D$D;'Kij
nEndPos = new long[nCount]; %RzkP}1>E
for(int i=0;i<nStartPos.length;i++) Lm0q/d2|\X
{ `d x.<R#,
nStartPos = input.readLong(); qjf4G[]!
nEndPos = input.readLong(); c"Q9ob
} V4W(>g
input.close(); $%ztP Ta
} D*_.4I
catch(IOException e){e.printStackTrace ();} uMZ<i}
catch(Exception e){e.printStackTrace ();} qA25P<
} - s{&_]A~
NjdDImz.;s
hsQ*ozv[)
private void processErrorCode(int nErrorCode) {t:*Xu
{ MQy,[y7I
System.err.println("Error Code : " + nErrorCode); EIg:@o&Jj
} k^s7s{
&##JZ
u=#_8e(9Z
//停止文件下载 z}*L*Sk
public void siteStop() mhs%8OTN
{ u2U+uD@yA
bStop = true; /de~+I5AB~
for(int i=0;i<nStartPos.length;i++) %Rm`YH?
fileSplitterFetch.splitterStop(); PA,\o8]x
[LbCG
C6D Eq>v
} \#"&S@%c
} )M56vyo
//负责部分文件的抓取 )Q|sW+AF
**FileSplitterFetch.java sE^=]N
*/ 3YEw7GIO-
package NetFox; y99|V39'
t-]~^s
xp\6,Jyh
import java.io.*; )Oj{x0{\Q
import java.net.*; sX`by\s,
|~Vq"6`
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public class FileSplitterFetch extends Thread { !4$o*{9Lx:
"T>;wyGW
S3c%</'
String sURL; //File URL /AUX7 m.8
long nStartPos; //File Snippet Start Position ? 8S~R
long nEndPos; //File Snippet End Position TLz>|gr
int nThreadID; //Thread's ID edlsS}8^
boolean bDownOver = false; //Downing is over UGA``;f
boolean bStop = false; //Stop identical i/,IG+4vI
FileAccessI fileAccessI = null; //File Access interface 3nUC,T%
'W~6-c9y
<2^ F'bQV
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x!?$y_t
{ zogl2e+
this.sURL = sURL; E/>kvs%
this.nStartPos = nStart; 5d)\Z0s
this.nEndPos = nEnd; 4L&Rs;
nThreadID = id; l?x'R("{
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TO] cZZ<
} ;\Pq
Z. xOO|
xK_0@6
public void run() .V l
{ <bh!wf6;
while(nStartPos < nEndPos && !bStop) :8lqo%5
{ su~J:~q
nYnv.5
Dq*O8*#*
try{ __-V_(/b,x
URL url = new URL(sURL); !L@a;L
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); *1U"uJno
httpConnection.setRequestProperty("User-Agent","NetFox"); qtS+01o
String sProperty = "bytes="+nStartPos+"-"; HQ/ Q"
httpConnection.setRequestProperty("RANGE",sProperty); G"*ch$:
Utility.log(sProperty); YH0utc
l-6W]\v Z
L:UPS&)
InputStream input = httpConnection.getInputStream(); Pbakw81!~
//logResponseHead(httpConnection); K5\;'.9M
/)XN^Jwa;m
n%ZOR1u)k#
byte[] b = new byte[1024]; wD $sKd
int nRead; @t3&#I}mc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )'$'?Fn
{ IoHYY:[-
nStartPos += fileAccessI.write(b,0,nRead); -W1Apd%>
//if(nThreadID == 1) <+p{U(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); b./MVz
} #]s&[O43
jd}-&DN
PW"uPn
Utility.log("Thread " + nThreadID + " is over!"); SbD B[O%
bDownOver = true; Z$Vd8U;
//nPos = fileAccessI.write (b,0,nRead); =XZd_v
} ?.69nN
catch(Exception e){e.printStackTrace ();} c(lG_"q6
} vC-5_pl
} Y:]m~-T
tS3{y*yi
dZ,~yV
//打印回应的头信息 Z!oq2,ia
public void logResponseHead(HttpURLConnection con) -D^v:aC
{ %j;mDR95
for(int i=1;;i++) K,f- w2!
{ VNxhv!w
String header=con.getHeaderFieldKey(i); Y i`wj^
if(header!=null) aHSl_[
//responseHeaders.put(header,httpConnection.getHeaderField(header)); *nV*WUS3
Utility.log(header+" : "+con.getHeaderField(header)); q,.@<sW
else (L!#2Jy
break; *#sY-Gd
} )'axJ
} ~x g#6%<=
f9?f!k
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public void splitterStop() dC8,
{ ,<]~/5-f
bStop = true; =~'{2gsB
} o=I.i>c
q#P@,|nc:
[Qn$i/`J
} c7t.
&>3AL,
Og9:MFI
/* Tu}?Q.pKo
**FileAccess.java &K-0ld(;
*//文件访问(定位，写) G[a&r
package NetFox; \@GKVssw
import java.io.*; W=!di3IA
FYX"q-Z
!)LVZfQ0
public class FileAccessI implements Serializable{ ZRj&k9D^U
71OQ?fc
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XjU/7Q
RandomAccessFile oSavedFile; ^,6c9Dxy
long nPos; j@Y'>3
CP6xyXOlPB
^;.&=3N,+
public FileAccessI() throws IOException \EQCR[7qu7
{ x\'95qU
this("",0); #A9rI;"XI
} oO&R3zA1d
EOzw&M];r
Ks\\2$Cm7
public FileAccessI(String sName,long nPos) throws IOException uu;1B.[b
{ gEkH5|*Y
oSavedFile = new RandomAccessFile(sName,"rw"); E}8wnrxf
this.nPos = nPos; {9<c*0l
oSavedFile.seek(nPos); +L|-W9"@3
} %p8#pt\$7
w)xfP^M#
i 3i
public synchronized int write(byte[] b,int nStart,int nLen) d9.~W5^fC
{ m-MfFEZ
int n = -1; P,={ C6*
try{ ja+PVf
oSavedFile.write(b,nStart,nLen); ]r(s02
n = nLen; aW;DfH
} N2$uw@s
catch(IOException e) %O\zYtQR
{ \??20iz
e.printStackTrace (); ^/DP%^D
} $Lt'xW`8
p{oc}dWin
$`6Q\=*R/
return n; cOvdC4
} s1%th"e [
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8>a%L?BY
} {P!1VYs5
4O:y ?D/e
F8d:7`lO@/
/* (KnU-E]L
**SiteInfoBean.java _tR?WmNH=
*/ *`~]XM@H
package NetFox; pMLTXqL
.1A/hAdU
QpiA~4
public class SiteInfoBean { Oe"nNvu/
(svKq(X
.r\|9 *j<
private String sSiteURL; //Site's URL /xw}]Fa5
private String sFilePath; //Saved File's Path G:i>MJbxT
private String sFileName; //Saved File's Name nr- 32u
private int nSplitter; //Count of Splited Downloading File AY_GD ^
D&!c7_^
hK 1 H'~c
public SiteInfoBean() ';KWHk8C
{//nSplitter的缺省值为5 84A:Rd'k3)
//default value of nSplitter is 5 't3&,:Y
this("","","",5); [K""6D
} pI1IDu*_Z
fHiS'R
\x<i6&.
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) e)*-<AGwC
{ 1w'W)x
sSiteURL= sURL; 6\vaR#
sFilePath = sPath; W=\45BJ
sFileName = sName; tx,q=.(
this.nSplitter = nSpiltter; @!p0<&R@x
l-?#oy
DAf0bh"
} jhH&}d9
) m(!lDz3
g+3_ $qIQ+
public String getSSiteURL() A\ r}V-
{ j]J-#J
return sSiteURL; m"GgaH3,
} C_S2a0?
3wN{k\ns
\Sv8c}8
public void setSSiteURL(String value) -1}&\=8M
{ +,T z +!
sSiteURL = value; >9<YQ(
} iCtS<"@Yx
i$lp8Y2ih
4)?s?+
public String getSFilePath() RwUosh\W
{ TW-^C;
return sFilePath; /z`.-D(
} |o<c`:;kt
sQBKzvFO3
Q PrP3DK
public void setSFilePath(String value) I+W:}}"j
{ k|`Qk!tr
sFilePath = value; eL88lV]I
} cy0j>-z
VWrb`p@
]DjnzClx
public String getSFileName() Scfe6+\EW
{ </!GU*
return sFileName; E?S
} ^j7>Ul,
*JF7 B
`Gh J)WA<
public void setSFileName(String value) pU1miA '
{ ;e6L@)dp9
sFileName = value; >!bw8lVV
} 'Lh nl3
Q'rgh+6
lP*p7Y '
public int getNSplitter() Og7^7))
{ $},_O8R
return nSplitter; a%r(F
} 1>L8EImx]V
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QYc/f"9
public void setNSplitter(int nCount) W:hTRq
{ E8L\3V4
nSplitter = nCount; lUd4`r"
} [*1:?mD$
} M)3'\x:
`#4q7v~>oe
'm0_pM1:D
/* y+h/jEbM</
**Utility.java Yf_/c*t\5
*/ -J>f,zA
package NetFox; d)GR]^=r
5E^P2Mlc
(dwb{+HW
public class Utility { RQU-]qQ8BM
E+cx8(
8>`8p0I$+
public Utility() Oj '^Ww m
{ $B`ETI9g-N
Vg}+w Nt5
cN`P5xP'
} VFq7nV/O
IV~5Y{(l
//线程睡眠 XZrzG P(
public static void sleep(int nSecond) !X`cNd)0Xo
{ ki|OowP
try{ IZuP{7p$
Thread.sleep(nSecond); +I+RNXR/{
} C!Jy;Z=+u
catch(Exception e) \+"Jg/)ij
{ 5xQ5)B4k
e.printStackTrace (); ]e$n;tuW
} 9<.8mW^68
} ?}HZJ@:lB
G"ixw
//日志 #'. '|z
public static void log(String sMsg) ZB]234`0
{ NR"C@3kD]o
System.err.println(sMsg); xVTl
} 5b->pc
-@Z9h)G|
{4*5Z[
public static void log(int sMsg) ' pIC~
{ bnN&E?{hF1
System.err.println(sMsg); ,6ae='=d
} D;z!C ys
} 9{0%M
c3WF!~1r
i!eY"|o
/* &%tW
**TestMethod.java oJ|m/i)
*/ G=l:v
package NetFox; l!": s:/'
bl{W{?QI
!Ej?9LHo
public class TestMethod { [LrO"9q(
zb s7G
VVfTFi<
public TestMethod() 9%2he)Yqc
{ ///xx/weblogic60b2_win.exe 92~$Qa\S!
try{ (a"/cH
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); sGE%zCB
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); OW#G{#.6R
SiteFileFetch fileFetch = new SiteFileFetch(bean); ";^_[n
fileFetch.start(); 7Rd(,eWE@
} qDgy7kkQ
catch(Exception e){e.printStackTrace ();} goNDS5}
bK{ VjXF
&'Xgf!x
} ?v`24p3PC
JW"`i
HY;kV6g{P
public static void main(String[] args) /J9Or{#r
{ 0IZF%`
new TestMethod(); %3. np
} dh1 N/[
} ED);2*qP}
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