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)); ,pQZ@I\z
} ;)z:fToh
for(int i=0;i<nEndPos.length-1;i++) bSi%2Onj
{ VSI9U3t3w
nEndPos = nStartPos[i+1]; Q%f^)HZGR
} g63(E,;;J
nEndPos[nEndPos.length-1] = nFileLength; J7Hl\Q[D1
} bP$dU,@p~
} e>7>j@(K]
jB Z&Ad@e
Q}K"24`=
//启动子线程 s %``H`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; M@H;pJ+B
for(int i=0;i<nStartPos.length;i++) 4ber!rJM
{ 'ud{m[|
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x$.^"l-vX
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5o'FS{6U
nStartPos,nEndPos,i); U!?_W=?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); dI@(<R
fileSplitterFetch.start(); 6"5A%{J
} 6"O+w=5B
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qHplJ "
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2M#Q.F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Ls$D$/:q?
nEndPos = " + nFileLength); N06OvU2>xU
// fileSplitterFetch[nPos.length-1].start(); "R1NG?;q
#64-~NVL_
(pCrmyB
//等待子线程结束 FQ7T'G![
//int count = 0; < #}5IQ5`Z
//是否结束while循环 ~IfJwBn-i
boolean breakWhile = false; tGh~!|P
Ms5ap<q#
HIR~"It$
while(!bStop) bz2ztH9 n
{ i$:*Pb3mV
write_nPos(); v6M6>&RR|
Utility.sleep(500); Vl/+;6_
breakWhile = true; d *|Y o
L~rBAIdD
vrhT<+q
for(int i=0;i<nStartPos.length;i++) JPc+rfF
{ 8:c-k|CX
if(!fileSplitterFetch.bDownOver) ]}-7_n#cC
{ rq/yD,I,
breakWhile = false; r6MMCJ|G
break; 3G)#5Lf<
} kHghPn?8]
} 2G67NC?+
if(breakWhile) RXpw!
break; rb2S7k0{
Jr ,;>
'EEJU/"u
//count++; ug!s7fo^
//if(count>4) J6s`'gFns
// siteStop(); qo90t{|c
} Ustv{:7v
<ro7vPKNa
uk<4+x,2)
System.err.println("文件下载结束！"); 8 S:w7Hr
} &Fzb6/
catch(Exception e){e.printStackTrace ();} B:;pvW]
} 8>2.UrC
j9x<Y]
fcRxp{*zO
//获得文件长度 _"Dv uR
public long getFileSize() 7a=gH2]&
{ L%*!`TN
int nFileLength = -1; hYT0l$Ng
try{ szZr4y<8|1
URL url = new URL(siteInfoBean.getSSiteURL()); e#L8X {f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); SIF/-{i(X
httpConnection.setRequestProperty("User-Agent","NetFox"); [fya)}
@Q ]=\N:
7 S#J>*
int responseCode=httpConnection.getResponseCode(); UqFO|r"M
if(responseCode>=400) E:sf{B'&
{ BOb">6C
processErrorCode(responseCode); JgKO|VO
return -2; //-2 represent access is error xjuN-
} ?*G|XnM&
c?f4Q,%|
f}#~-.NGs
String sHeader; c@!_/0
$Uq|w[LA
-[4T
for(int i=1;;i++) (^8Y|:Tz
{ ~drS} V
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); zH?!
//Utility.log(in.readLine()); jH5 k
sHeader=httpConnection.getHeaderFieldKey(i); l[mWf
if(sHeader!=null) 4C6YO
{ 6"LcJ%o
if(sHeader.equals("Content-Length")) U2tV4_ e
{ &Cq`Y !y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 75cW_t,g
break; {NmWQyEv
} T6y\|
} 'Vzp2
else EA@.,7F
break; i^X]j
} xBThq?N?
} zsEc(
catch(IOException e){e.printStackTrace ();} BM%e0n7
catch(Exception e){e.printStackTrace ();} APn|\
m)ky*"(
:[p}
Utility.log(nFileLength); 59LZv-l
)al]*[lY
-]N x,{
return nFileLength; 9tU]`f
} .KB^3pOpx
2@n{yYwy
X[-xowE-
//保存下载信息（文件指针位置） `&r+F/Ap2
private void write_nPos() s[RAHU
{ dc+>m,3$
try{ |IeTqEu9
output = new DataOutputStream(new FileOutputStream(tmpFile)); 7Kr*P<-G
output.writeInt(nStartPos.length); {g'(~ qv
for(int i=0;i<nStartPos.length;i++) <prk8jSWV
{ OZb-:!m*
// output.writeLong(nPos); FZ{h?#2?
output.writeLong(fileSplitterFetch.nStartPos); [SjqOTon{
output.writeLong(fileSplitterFetch.nEndPos); jnkR}wAA
} (+w*[qHe
output.close(); h"[AOfTE$
} MD}w Y><C
catch(IOException e){e.printStackTrace ();} f&NgS+<K$
catch(Exception e){e.printStackTrace ();} pxA?
} A9KET$i@v
.Yamc#A-
>2y':fO
//读取保存的下载信息（文件指针位置） %8RrRW
private void read_nPos() A]_7}<<N
{ NlA,'`,
try{ 2jA{SY-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5c@,bIl *
int nCount = input.readInt(); >2Y=*K,:
nStartPos = new long[nCount]; ]{;gw<T
nEndPos = new long[nCount]; $g^@AdE%
for(int i=0;i<nStartPos.length;i++) KaLzg5is
{ Z\(q@3C
nStartPos = input.readLong(); -vAC"8)S
nEndPos = input.readLong(); AmUr.ofu
} SpIv#?
input.close(); [$ubNk;!z
} z{%<<pZ
catch(IOException e){e.printStackTrace ();} @f_Lp%K
catch(Exception e){e.printStackTrace ();} W-$Z(Z XL
} ")1:F>
*l(7D(#
WJ]T\DI
private void processErrorCode(int nErrorCode) *[Imn\hu
{ `Y0%cXi3
System.err.println("Error Code : " + nErrorCode); m;$b'pT
} ,5P0S0*{
[CTnXb
'9%\;
//停止文件下载 k`cfG\;r
public void siteStop() ^L,K& Jd
{ =bAx,,D#
bStop = true; ]"pVj6O
for(int i=0;i<nStartPos.length;i++) +X\FBvP&
fileSplitterFetch.splitterStop(); dUD[e,?
vJLK,[
s2a{>II6
} {Ea b j
} xf'V{9*
//负责部分文件的抓取 5p,RI&nlN
**FileSplitterFetch.java W Tcw4
*/ ;_XFo&@
package NetFox; K,tQ!kk
;gD})@
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import java.io.*; ./XYd"p
import java.net.*; Ml`:UrU
xW+6qtG`
!@5 9)
public class FileSplitterFetch extends Thread { `](e:be}
qfX6TV5J}!
44J]I\+
String sURL; //File URL Mg+2. 8%
long nStartPos; //File Snippet Start Position A_rGt?i
long nEndPos; //File Snippet End Position i[i4h"$0
int nThreadID; //Thread's ID 0RzEY!9g+
boolean bDownOver = false; //Downing is over M^A48u{,"
boolean bStop = false; //Stop identical I !- U'{
FileAccessI fileAccessI = null; //File Access interface C;v.S5x
{% 6}'
9FF0%*tGo
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s$IDLs,WM
{ AI2~Jp
this.sURL = sURL; [=C6U_vU
this.nStartPos = nStart; v<k?Vu
this.nEndPos = nEnd; ;cNv\t
nThreadID = id; 2bz2KB5>
fileAccessI = new FileAccessI(sName,nStartPos);//定位 //B&k`u
} -$\y_?}
&.3"Uo\#
&*o=I|pQ
public void run() }ZYd4h|g\z
{ 3s*mbk[J
while(nStartPos < nEndPos && !bStop) XMZ,Y7
{ {.`vs;U
@?ebuj5{e
P|`8}|}a
try{ pR<`H'
URL url = new URL(sURL); SV4E0c>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); p;a,#IJu
httpConnection.setRequestProperty("User-Agent","NetFox"); v{RZJ^1
String sProperty = "bytes="+nStartPos+"-"; #{0HYg?(f
httpConnection.setRequestProperty("RANGE",sProperty); W@>% {eE
Utility.log(sProperty); &{5,:%PXw
UJUEYG
KV91)U
InputStream input = httpConnection.getInputStream(); \eTwXe]Pv
//logResponseHead(httpConnection); G+9,,`2
0mp/Le5
qyb?49I
byte[] b = new byte[1024]; t[HE6ea
int nRead; VD AaYDi
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "37lx;CH
{ v4<nI;Ux
nStartPos += fileAccessI.write(b,0,nRead); /*~EO{o
//if(nThreadID == 1) $B+8Of
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Q)#B0NA;T
} SZ7:u895E
?9vuuIE
m<G,[Yc
Utility.log("Thread " + nThreadID + " is over!"); Lpkyoh v
bDownOver = true; t mntp
//nPos = fileAccessI.write (b,0,nRead); wKh4|Ka
} j{ ]I]\=?
catch(Exception e){e.printStackTrace ();} alJ)^OSIe
} 2F;y;l%
} E#34Wh2z
_>?\DgjH
k:i4=5^*GX
//打印回应的头信息 z9f-.72"X
public void logResponseHead(HttpURLConnection con) /A\8 mL8
{ 'd0~!w
for(int i=1;;i++) 810|Tj*U%
{ c?Y*Y
String header=con.getHeaderFieldKey(i); AD>e?u
if(header!=null) :]K4KFM
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Z9E\,Ly
Utility.log(header+" : "+con.getHeaderField(header)); `%bypHeSp
else !vi>U|rh
break; D_2:k'4
} Q>qUk@
} ux-/>enc
umBICC]CU
W ~<^L\Lu
public void splitterStop() y8y5*e~A-)
{ 1dY}\Sp
bStop = true; Cl.x'v
} !<|4C6X:4
sfH_5 #w
Sz $~P9
} Oamg]ST
]OhiYU4
$QF{iV@6d4
/* f^ZRT@`O
**FileAccess.java Rr$-tYy6
*//文件访问(定位，写) Oxnp0 s
package NetFox; 2ACCh4(/P
import java.io.*; Eh`7X=Z7E
Ufj`euY
KM0ru
public class FileAccessI implements Serializable{ T.F!+
QhFVxCA
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "9uKtQS0o
RandomAccessFile oSavedFile; .<?GS{6 N
long nPos; yF:1( 4
0JS?;fk
bRDYGuC
public FileAccessI() throws IOException e ,'_xV
{ E`JI>7
this("",0); 234p9A@
} o 11jca|
Xq4O@V
E =67e=h
public FileAccessI(String sName,long nPos) throws IOException R-wp9^
{ ^6x%*/l|
oSavedFile = new RandomAccessFile(sName,"rw"); Hvauyx5T
this.nPos = nPos; ^0)g/`H^>
oSavedFile.seek(nPos); G't$Qx,IC
} GKqm&/M*=
;O5zUl-`
Ty\R=y}}
public synchronized int write(byte[] b,int nStart,int nLen) ;C#F>SG\S
{ HWAdhDZ
int n = -1; %Xg4b6<9
try{ P:S.~Jq
oSavedFile.write(b,nStart,nLen); \w>y`\6mX
n = nLen; hFUlNJ
} Q}JOU
catch(IOException e) 2W(s(-hD
{ m 0C@G5
e.printStackTrace (); X05/uX{
} h&iC;yj=
P5V}#;v
6wRd<]C
return n; 8nqG<!,q
} s[*rzoA
.sW|Id )
ODN/G%l
} Paq4
2qNt,;DQ
@;4zrzQi7
/* MY)O^I X$
**SiteInfoBean.java +E+p"7
*/ rKc9b<Ir
package NetFox; s^TZXCyF o
n6>#/eUH
]cvwIc">
public class SiteInfoBean { 0auYG><=
FUzzB94a
K3m/(jdO
private String sSiteURL; //Site's URL -ad{tJV|
private String sFilePath; //Saved File's Path :kV#y
private String sFileName; //Saved File's Name }#+^{P3;
private int nSplitter; //Count of Splited Downloading File }&D WaO]J7
{WS;dX4
klYX7?
public SiteInfoBean() rXq.DvQ
{//nSplitter的缺省值为5 c#]4awHU
//default value of nSplitter is 5 3`?7<YJ
this("","","",5); T<>,lQs(a
} .43'HV
Y-z(zS^1
\l0[rcEf
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =%O6:YM
{ fbvL7* (
sSiteURL= sURL; /s?`&1v|r
sFilePath = sPath; A\DCW
sFileName = sName; S@tLCqV4
this.nSplitter = nSpiltter; ^ +\dz
#%2rP'He
5;WH:XM
} ;;t yoh~t
(,2SXV
h"W,WxL8
public String getSSiteURL() A{zN| S[
{ (mB&m@-N
return sSiteURL; 2pCaX\t
} %2{ye
Q{>k1$fkV
T763:v
public void setSSiteURL(String value) ?j.,Nw4FC
{ C): 1?@
sSiteURL = value; Nx;~@
} ~8+ Zs
1GRCV8"Z^
>R_&Ouh:
public String getSFilePath() >'$Mp<
{ Y@iS_lR
return sFilePath; N~gzDQ3
} ejd(R+
/nsX]V6i
pki%vRY
public void setSFilePath(String value) r5/0u(\LB
{ FV!q!D
sFilePath = value; T::85
} \@zHON(
gJ{)-\
Fo_sgv8O<
public String getSFileName() ~?}Emn;t
{ !<";cw(q
return sFileName; J;e2&gB
} C) s5D
0+ '&`Q!u
5tkAFb4P
public void setSFileName(String value) =qIp2c}Rx
{ B$K=\6o
sFileName = value; Q&;9x?e
} ?V=ZIGj
ru%y
EZGIf/ 3
public int getNSplitter() eByz-,{P
{ e*C(q~PQ
return nSplitter; _H%c;z+
} B3I`40#
HC8e>kP9b
'<<t]kK[N
public void setNSplitter(int nCount) L*+@>3mu)
{ ITBE|b
nSplitter = nCount; (ZizuHC
} F>l] 9!P|m
} ?l )[7LR4
Avc%2+
\\qZl)P_
/* ^x,YW]AS}
**Utility.java O/Crd/
*/ t:Q*gWRh
package NetFox; Lq^)R
{\5
=T@1@w
public class Utility { q9_OGd|P
* u>\57W
o.!Dq7R
public Utility() M }D}K\)
{ 2ilQXy
vE?G7%,
HV|,}Wks6s
} r19 pZAc
Otuf]B^s
//线程睡眠 S\=Nn7"
public static void sleep(int nSecond) )t#W{Gzfmh
{ TJRCH>E[a
try{ ^h6tr8yn
Thread.sleep(nSecond); R 9\*#c
} Yq KCeg
catch(Exception e) %u'ukcL7
{ 6&x@.1('z
e.printStackTrace (); 7:1Lol-V
} c@7rqHU-0
} p5iuYHKk?
ez$(c
//日志 Rm( "=(
public static void log(String sMsg) }7Q%6&IR
{ ga+dt
System.err.println(sMsg); y)@wjH{6
} K0>zxqY
yN-9[P8C
0(HU}I
public static void log(int sMsg) f:} x7_Q
{ sgFEK[w.y
System.err.println(sMsg); k,*XG$2h
} mzgfFNm^G)
} Zy/_ E@C}u
hgq;`_;1,
0=YI@@n)
/* qE"OB
**TestMethod.java zDG b7S{
*/ z03K=aZ
package NetFox; 9'B `]/L
WyiQoN'q
|6-nbj
public class TestMethod { 9*M,R,y
@yYkti;4-
zb3tIRH
public TestMethod() =s6 opL)
{ ///xx/weblogic60b2_win.exe 59u}W 0
try{ 2?Vd5xkt
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 'g\4O3&_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); H5|;{q:j
SiteFileFetch fileFetch = new SiteFileFetch(bean); Pm7}"D'/
fileFetch.start(); tw@X> G1z
} @0''k
catch(Exception e){e.printStackTrace ();} jP.dDYc
8s@3hXD&
>t+P(*u
} (bS&D/N.
h?U O&(
"{t$nVJ
public static void main(String[] args) P%n>Tg80M
{ a<e[e>
new TestMethod(); (ZlU^Gw#UB
} z1a7*)8P
} u ga_T
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