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)); ke_Dd?
} dy N`9
for(int i=0;i<nEndPos.length-1;i++) 3ddH@Y|
{ Zm& X $U
nEndPos = nStartPos[i+1]; li;Np5P
} GV#"2{t j
nEndPos[nEndPos.length-1] = nFileLength; (.4mX t
} W4Rs9NA}
} :"7V,UP @
T5?@'b8F6
SjV;& 1Z/
//启动子线程 fC+<n{"C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'hfQ4EN
for(int i=0;i<nStartPos.length;i++) hd1(q33
{ x~C%Hp*#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Sx?IpcPSm
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^+tAgK2
nStartPos,nEndPos,i); L^uO.eI"m
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Cp=DdmR
fileSplitterFetch.start(); -:b0fKn
} hZf0q 2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), lgFA}p@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); W- 5Z"m1I
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'AU(WHf
nEndPos = " + nFileLength); p9rnhqH6
// fileSplitterFetch[nPos.length-1].start(); ce-5XqzY@
`K37&b;`[
8gWifx #N
//等待子线程结束 XoEiW R
//int count = 0; hi4#8W
//是否结束while循环 l\<*9m<
boolean breakWhile = false; 6=A
D_er(
1uBnU2E
while(!bStop) m[7@l
{ 89ivyv;]U
write_nPos(); qE?*:$
Utility.sleep(500); vpu20?E>5z
breakWhile = true; `7$0H]*6
5/4N Y
l2Z!;Wm(
for(int i=0;i<nStartPos.length;i++) ^x(BZolkm
{ &6 .r=,BO
if(!fileSplitterFetch.bDownOver) e<o{3*%p)
{ tmEF7e`(o
breakWhile = false; YLs%u=e($
break; S_?{<{
} |35"V3bs
} @9S3u#vP
if(breakWhile) 'jh9n7mH
break; .:gZ*ks~
GBnf]A,^@
8U}BSM_<2
//count++; @vzv9c[
//if(count>4) +Y;/10p
// siteStop(); pIcvsd
} trD-qi
*b#00)d
j"g[qF/*
System.err.println("文件下载结束！"); 2MS-e}mi
} Q'-g+aN
catch(Exception e){e.printStackTrace ();} 9w\yWxl
} i2$7nSQ9
cb|cYCo5
qy@v,a
//获得文件长度 .3Ex=aQcX
public long getFileSize() kB~KC-&O
{ ig G8L
int nFileLength = -1; `-Yo$b;:
try{ G&ZpQ)
URL url = new URL(siteInfoBean.getSSiteURL()); ]M2<b:yo
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6,Aj5jG
httpConnection.setRequestProperty("User-Agent","NetFox"); #a7 Wx}
4rXjso|
j;%RV)e
int responseCode=httpConnection.getResponseCode(); E(t:F^z&D
if(responseCode>=400) "h.-qQGU%
{ bWp40&vx
processErrorCode(responseCode); E1'| ;}/
return -2; //-2 represent access is error }M_Yn0(3
} {zGM[A
N0U6N< w
^)-* Ubzz
String sHeader; s^O>PEX&<I
.4I"[$?Q
M? 7CBqZ
for(int i=1;;i++) ]*fiLYe9
{ +[W_Jz
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @C\>P49
//Utility.log(in.readLine()); UC@&! kM
sHeader=httpConnection.getHeaderFieldKey(i); <\0+*`">g
if(sHeader!=null) H~fX>6>
{ i;+]Y
if(sHeader.equals("Content-Length")) wXj!bh8\r
{ E]Wnl\Be
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); AfQ?jKk&{'
break; ChVur{jR
} %M?A>7b
} e-@=QI^,
else &RSUB;ymL
break; s]=bg+v?j
} Ndb_|
} ,gdf7&r
catch(IOException e){e.printStackTrace ();} D I` M
catch(Exception e){e.printStackTrace ();} :Ng4? +@r
KDt@Xi6||
drv"I[}{A
Utility.log(nFileLength); IiX`l6L~W
ZH@BHg|}H
gOk<pRcTb=
return nFileLength; A4kYEA
} g 0=Q>TzY
HTpoYxn(
RU r0K#]
//保存下载信息（文件指针位置） jg,oGtRz
private void write_nPos() cwe@W PE2
{ f;Cu@z{b
try{ ^N{Lau
output = new DataOutputStream(new FileOutputStream(tmpFile)); T(n<@Ac]V
output.writeInt(nStartPos.length); WKHEU)'!
for(int i=0;i<nStartPos.length;i++) ,{KjVv<
{ NZj_7j|o9
// output.writeLong(nPos); rSGt`#E-s.
output.writeLong(fileSplitterFetch.nStartPos); a.oZ}R7'Y
output.writeLong(fileSplitterFetch.nEndPos); DA0{s
} {e>E4(
output.close(); FN-j@
} WJB/X"J
catch(IOException e){e.printStackTrace ();} 8ec6J*b
catch(Exception e){e.printStackTrace ();} ZO^Y9\L
} %`o3YR
C>1fL6ct
M*& tVG
//读取保存的下载信息（文件指针位置） X={n9*Sd8
private void read_nPos() kX\\t.nH
{ !W^b:qjJ
try{ |~6X: M61
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); z / YF7wrx
int nCount = input.readInt(); =z=$S]qN
nStartPos = new long[nCount]; }w,^]fC:
nEndPos = new long[nCount]; wUd6xR
for(int i=0;i<nStartPos.length;i++) !jV}sp<Xp
{ R0 g-
nStartPos = input.readLong(); jK#[r[q{
nEndPos = input.readLong(); `L-GI{EJ
} wEMh !jAbv
input.close(); p@/i e@DX
} }s0?RH
catch(IOException e){e.printStackTrace ();} ` 0YI?$G1
catch(Exception e){e.printStackTrace ();} jz\LI
} ~"oxytJ
L_3undy,
~|LlT^C
private void processErrorCode(int nErrorCode) 5<?O S &B
{ aNqhxvwf
System.err.println("Error Code : " + nErrorCode); Z#n!=kTTm
} **zh>Y}6
qkCj33v
tkN5|95
//停止文件下载 [Rqv49n*V
public void siteStop() r%*UU4xvB
{ `M "O #
bStop = true; sj)$o94=
for(int i=0;i<nStartPos.length;i++) rv(Qz|K@
fileSplitterFetch.splitterStop(); ^,Paih 2
JN9 W:X.
&&N]u e@>
} xB1Oh+@i
} l7{Xy_66
//负责部分文件的抓取 sC8C><y
**FileSplitterFetch.java 9~6FWBt
*/ IX!Q X
package NetFox; G8m:]!
"Qf X&'09
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import java.io.*; g\ r%A
import java.net.*; 7$ vs X
g]^@bxdg
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public class FileSplitterFetch extends Thread { &E0d{2
b' 1%g}
$wL zaZL|
String sURL; //File URL 2}Ga
long nStartPos; //File Snippet Start Position }O_kbPNw
long nEndPos; //File Snippet End Position [P5+}@t
int nThreadID; //Thread's ID h J*2q"
boolean bDownOver = false; //Downing is over by 'P}
boolean bStop = false; //Stop identical 0n5{Wr$
FileAccessI fileAccessI = null; //File Access interface J{W<6AK\S
MP5 vc5[
dQD YN_
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p 8,wr )
{ ~x:\xQti
this.sURL = sURL; .>4Zt'gCt
this.nStartPos = nStart; [If%+mHdU
this.nEndPos = nEnd; Z`L-UQJ.
nThreadID = id; gq[|>Rs75
fileAccessI = new FileAccessI(sName,nStartPos);//定位 D6cqON0a.
} clE_a?
)bJS*#
jH+ddBVA
public void run() 2g>4fZ
{ G}!dm0s$
while(nStartPos < nEndPos && !bStop) V)[ta`9
{ ,(h:0L2v7d
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y|sU-O2}Dl
try{ ~RlsgtX"
URL url = new URL(sURL); }.j<kmd
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); A 9I5
httpConnection.setRequestProperty("User-Agent","NetFox"); CCZ'(Tkq
String sProperty = "bytes="+nStartPos+"-"; B=E<</i
httpConnection.setRequestProperty("RANGE",sProperty); (o+(YV^
Utility.log(sProperty); L>4!@L5)
S;pKL,d>r
^[]q/v'3m!
InputStream input = httpConnection.getInputStream(); 1}O&q6\"J
//logResponseHead(httpConnection); ${(c`X
y5"b(nb
2vb{PQ
byte[] b = new byte[1024]; \Y37wy4
int nRead; Dt)O60X3>
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Ancka
{ *{_WM}G
nStartPos += fileAccessI.write(b,0,nRead); 7w}PYp1Z'~
//if(nThreadID == 1) 0A]+9@W;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); BKd03s=
} WA~PE` U
Z/Vb_
fdU`+[_
Utility.log("Thread " + nThreadID + " is over!"); Y~FN`=O
bDownOver = true; I.C,y\
//nPos = fileAccessI.write (b,0,nRead); mmN!=mf*
} n'WhCrW
catch(Exception e){e.printStackTrace ();} U|[+M@F_L
} xN^ngRg0
} `5J`<BPs
l"T{!Oq
p#k>BHgnF
//打印回应的头信息 )GbVgYkk
public void logResponseHead(HttpURLConnection con) UW!*=?h
{ Ub>Pl,~'
for(int i=1;;i++) fga{b7
{ Cf~H9
String header=con.getHeaderFieldKey(i); bcVzl]9
if(header!=null) oRp;9
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Cob<N'.
Utility.log(header+" : "+con.getHeaderField(header)); 5V"Fy&}:
else `W&:*
break; P#gY-k&Nr
} c8R#=^ DD
} EWU(Al T
&Fw8V=Pw
Or({|S9d2
public void splitterStop() Cp`>dtCd
{ W*S!}ZT`
bStop = true; :J 7p=sX
} zi7>!#(
>Rnj6A|Q
q?9x0L
} R)[ l3
|FR'?y1
$y2"Q,n+
/* JGLjx"Y
**FileAccess.java (Lp$EC&%6
*//文件访问(定位，写) h2Kx
package NetFox; P7X':
import java.io.*; {6/Yu:;
q#=}T~4j
! u4'1jd[d
public class FileAccessI implements Serializable{ W5&;PkhQ6
CO)BF%?B
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 /d1 B-I
RandomAccessFile oSavedFile; CyWaXp65
long nPos; ljS~>&
/q3]AVV
t V]BcDp
public FileAccessI() throws IOException _&]B
{ nMBKZ
this("",0); ;X9nYH
} zG[GyyAQ
uyp|Xh,
SccaX P
public FileAccessI(String sName,long nPos) throws IOException |q( .j4[i
{ Zy<gA >
oSavedFile = new RandomAccessFile(sName,"rw"); V~9s+>
this.nPos = nPos; DGQGV[9%4C
oSavedFile.seek(nPos); YNRorE
} nw)yK%`;M
R cz;|h8
2G(RQ\Ro*
public synchronized int write(byte[] b,int nStart,int nLen) OJ/l}_a
{ )S,Rx
int n = -1; o'`:$ (
try{ ,[Bv\4Ah
oSavedFile.write(b,nStart,nLen); sfN6ro
n = nLen; b/yXE)3 X
} 8 <~E;:
catch(IOException e) {dbPMx
{ A<+veqb4
e.printStackTrace (); #y?iUv
} 3=)!9;uY
7M#irCX
sK&[sN33
return n; h"/y$
} 5 wT e?
j3J\%7^i
1U/ dc.x5
} y1FE +EX[
E&wz0d;gf
Pf4b/w/
/* ??7c9l5,
**SiteInfoBean.java :B(vk3;U!
*/ 3g#
package NetFox; "s6\l~+9l
X<j(AAHE
Q.$|TbVfds
public class SiteInfoBean { E76#xsyhF
_T{ "F
{Y(#<UDM
private String sSiteURL; //Site's URL Jw b'5[R
private String sFilePath; //Saved File's Path %+{[%?xh
private String sFileName; //Saved File's Name Fr,qVYf
private int nSplitter; //Count of Splited Downloading File m! 3e>cI
uE]kv
z+k[HE^S
public SiteInfoBean() 'Pm.b}p<
{//nSplitter的缺省值为5 {?zBc E:
//default value of nSplitter is 5 SFiK_;
this("","","",5); |k:ecw
} d<@SRHP(
G%RL8HU
[PI!.9H
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k\NwH?ppu
{ qpCNvhi
sSiteURL= sURL; RXbhuI
sFilePath = sPath; mk'$ |2O
sFileName = sName; bh~"LQS1
this.nSplitter = nSpiltter; GlPd)m`
zBKfaQI,
jk\04k
} \mIm}+!H
G""L1?
h,(f3Ik0O
public String getSSiteURL() ?e. Ge0&
{ ,1!~@dhs
return sSiteURL; \uUd *
} #j?SdQ
I/HcIBJ
A@o:mZ+XN(
public void setSSiteURL(String value) w9W0j
{ @|i f^
sSiteURL = value; q"uP%TN
} RaBq@r*(
"{lw;AA5F
p3L0'rY|+
public String getSFilePath() mx ]a@tu
{ *Bj7\8cKC
return sFilePath; GcpAj9
} ]5_6m;g
Ug1[pONk
?L'4*S]
public void setSFilePath(String value) D rMG{Yiu
{ l[cBDNlrC;
sFilePath = value; bY>JLRQJ-
} 1;Q>B>6
n1mqe*Mvs/
:9=J=G*
public String getSFileName() [/Figr]
{ f]*_]J/
return sFileName; &AS<2hB
} ]\8{z"
YcQ3:i
CQ( _$
public void setSFileName(String value) u]Eyb),Gy
{ -l ?J
sFileName = value; <.l$jW]
} \kQ@G
mK);NvJ!
cfg_xrW0^
public int getNSplitter() )RFE< Qcj
{ 5YQq*$|'+
return nSplitter; , id`=L=
} F[65)"^
jcuC2t
<r1N6(n
public void setNSplitter(int nCount) EXrOP]Kl
{ EA/+~ux
nSplitter = nCount; _s&sA2r<
} 'g$a.75/-
} 2Y2J)5,
'B$bGQ
HVz,liq
/* :2\H>^uV
**Utility.java /JOEnQ5X\!
*/ ZYBK'&J4m
package NetFox; 7T)J{:+0!|
N;.cZp2
j1LL[+G-"_
public class Utility { R\oas"
DJF-J#
wW1E 'Vy{
public Utility() 7r_Y.
{ OSvv\3=
1HBdIWhHv.
xP1`FSO8=
} abvA*|
:h|nV ~
//线程睡眠 x4HVB
public static void sleep(int nSecond) I'_.U]An
{ $jDp ^ -
try{ A#"AqNVWv
Thread.sleep(nSecond); 3j2% '$>E^
} p:,(r{*?
catch(Exception e) mST/u>'
{ -9 AI@^q
e.printStackTrace (); )eFq0+6*)
} JQ*CF(9
} NINaOs
hE-u9i
//日志 \mt0mv;c
public static void log(String sMsg) GUe&WW:Sqk
{ A3UC=z<y
System.err.println(sMsg); <*Kj7o{Qn
} d.7pc P
=9oN#4mWK
C#5z!z/:%
public static void log(int sMsg) | Wrf|%p
{ >Ic)RPO9
System.err.println(sMsg); (wNL,<%~
} FS%Xq-c
} T[iwP~l
(aX5VB**
Ny;(1N|&3
/* B_k[N}|zD
**TestMethod.java *Mt's[8
*/ 1RtbQ{2F;
package NetFox; Ksq{=q-T
RNyw`>
)w8h2=l
public class TestMethod { 4Lx#5}P
"%aJ'l2
C?bq7kD:H
public TestMethod() "28b&pm
{ ///xx/weblogic60b2_win.exe p;dH[NW
try{ \e5bxc
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 21$YZlhJ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o;XzJ#P
SiteFileFetch fileFetch = new SiteFileFetch(bean); -d+q+l>0
fileFetch.start(); -<gGNj.x-
} A0SEzX({[
catch(Exception e){e.printStackTrace ();} ~+{OSx<S
C@` eYi
V`V Z[
} #h@/~xr
?Sj3-*/?
swvn*xr
public static void main(String[] args) vMsb@@O\\
{ F:.rb Ei
new TestMethod(); 6,sZo!G
} AF4:v<EN
} W8Z&J18AU
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